So I went over all the comments again and tried to categorize the opinions (trying to filter out those who already replied earlier with same or similar arguments.
Here is the result with the 15 most mentioned reasons of not using Linux on the desktop - from the opions of the discussing people (the red ones I consider in fact being issues to be solved, my comments in italic):
- Slick Microsoft PR, Windows is the defacto standard or simply inherited monopoly. (18 votes)
This is a fact, but not a reason for using Windows. If so, we would still ride on horses and don't have cars - just because horses were a monopoly for traveling (related to 11.)...
- Missing appropriate software on Linux (for particular needs) / Vendor Lock-in. (18 votes) - Mentioned were in detail: Branch specific, special used apps not platform independent and/or not integrated well, AD, Deployment, AS400, Sage, Meeting- and Conference-Software, Photoshop, Exchange-Integration, Smart-Phone-Integration, AutoCAD, Screen Reader, ...
Yes, this is really an issue - and that is because the fact mentioned above in 1. and hence followed by 6. The result is that many developers and software companies still just focus on Windows.
- Compatibility issues Linux-Windows in software when collaborating. (13 votes) - Mentioned were in detail: MS Office vs OpenOffice/LibreOffice, some proprietary formats can't be read, Domain-Integration, Some websites are IE only, General compatibility-fears.
The MSO vs OOL/LO issue is a really big one because many people write many documents and many people need to collaborate. There are many compatibility issues - already between different versions of Microsoft Office. The 2007 and 2010 docx, xlsx, pptx formats (yes, we have already two variants of the *x-formats) introduce a lot of possible conversion/open/save problems. I could write a long blog post just about those issues. Domain integration I do not consider important as I find the whole domain system outdated looking at current company structures (increasing cooperations between separate companies for example) and how they evolve. To develop IE-only websites nowadays is still done - although completely free of sense.
- Too much tech-knowhow needed (just for nerds, servers and/or for commandline junkies). (11 votes)
In reality, if you want good work to be done, on Windows you also need much in-depth knowhow. It's just, that quite every guy or girl, spent hours in front of the computer gaming, already considers himself/herself a computer guru...
What simply is not true is, that you need to be a commandline junkie or a nerd to use Linux. Those days are a long gone - Linux has graphical environment!
- People already know Windows and are simply resistant to change (and will struggle). (10 votes)
Most people I met who showed resistance when I talked about Linux, weren't interested that much because they do not use computers that much - use it only when necessary for writing an email or surf some website. Those can be considered to be resistant to computers in general. Although even those could have a better computer experience going Linux, it's usually best to just let them continue until the next virus has biten their OS to death.
- Lack of awareness / Ignorance or simply decision of management. (9 votes)
Yes, is an issue. People simple don't open their eyes. This point is somehow related to 5. I found that most people currently in management, grew up with Windows. That's simply their comfort zone and usually they are so busy and so convinced of themselves that they simply don't consider anything different. This will change over the years, when more people grow up with Macs or Linux machines. I do trust, that even without active marketing, people will notice the advantages plus their current suffering and move over slowly.
- (Migration) costs (get it to work, experience, train users etc). (9 votes)
Related to 10. Of course, when considering a big change (and changing OS in a company is a big change anyway), investment is needed. I also have invested a lot of time into learning Linux, which only at the beginning is really tough until you understood some core things. And for the admins there is a lot more to learn than for the users. In my case I was so annoyed by Windows and the continuous suffering that - when I started - I was sure, it will be worth the investment - and it was! And honestly: Switching from XP to Windows 7 or from Office 2003 to 2010 is also eating a lot of money and requires additional training for the users.
- Missing Linux Knowhow (and not enough time to dig into it). (7 votes)
Related to 7. Of course, in the beginning there is missing know-how. But seriously: Switching from Windows Server 2003 to Server 2008r2 also required additional know-how - even worse - you think, you know it, but then you oversee some relevant changes (like the syswow64 registry hive and separate 32-bit executables in that folder) during your first attempts. You have to struggle with the new versions because Microsoft urges you by quitting support for the older OS versions. In reality you don't even have time to dig into the new Windows details, isn't it? - New details, new problems...
- Hardware compatibility issues. (7 votes)
Yes, you need to take care (which the normal default user does not - or cannot - when buying a new PC). I had problems with particular WLAN-cards, Bluetooth-adapters, sound and video cards first of all. Issue can be widely reduced by buying officially certified hardware for example (either by Canonical or the hardware vendor for example). Dell and Lenovo for example are vendors known to be very compatible with Linux (anyway you need to look at the particular model or just ask the vendor or partner of your choice). I usually recommend people: When buying, tell them that you want a Linux-compatible model - otherwise you will return it back).
- Less educated specialists/administrators available or cost more. (7 votes)
Related to 7. - I am pretty sure that a real good Windows administrator will also ask more. By tendency, there are more people working in Windows environment, but total number of real specialists I think is not significantly more than in Linux world. But I understand, that this can be an issue for a medium-sized or small company just watching out for the cheap administrator around the corner.
- People don't want to run risks and do what the others do (using the market leader). (6 votes)
Related to 1. Of course, if you do something new and you fail, people might argue and ask why the hack you didn't follow what the "expert" says. When you do something new then of course you make mistakes - but you will learn and get know-how. But you can do what fits for you. Doing, what the major part of others do (or recommend), you will never get, what really fits really good for your company.
- Better support (because you pay for the software and have a contract). (6 votes)
This is completely wrong! You can also get payed support in open source world and a commercial company does never give you the guarantee of continued maintenance. In fact I already invested into software technologies and then the vendor discontinued the product (without selling it to somebody else - just let it die). The history of Open Office and Libre Office shows us, that open source is even the better path here. Oracle thinking of unacceptable changes? - The project was forked quasi in an instant! As long there are some folks being interested in it, it can continue to life - even if it's just you - it's your choice.
- Windows already there on the shipped PC. (6 votes)
I have never ever kept the default installation on a PC - neither when I was still using Windows. In most cases it already started with partitioning that was not fitting my desires or needs. Next could be OS language or preinstalled software. And a Linux installation can be either done by a novice - it's easy (at least the Ubuntu, Mint or Fedora distributions - beside others). The only very annoying thing with a Windows preinstalled is: You already paid the license fee to Microsoft in that case and I am pretty sure, that Microsoft is not sad about it, if you overwrite your OS with Linux because: You don't consume bandwith, don't call support, don't ask stupid questions in forums etc - you pay without either asking a service for it...
- Too much confusion because many distros, desktop environments. (6 votes)
Are you confused and don't know what to use? - No problem, I do recommend Ubuntu with it's default desktop - and choose the LTS version. If you don't have an idea what you might want, Ubuntu for sure won't be a bad choice. But the point is: You have the choice! People work in different ways, have different priorities and have different jobs. You might discover later that you prefer a different distribution. You may consult distrowatch.com. At this point I still find the Ubuntu distribution the most stable one (regarding the complete set of applications existing around) offering everything I need regarding features and additional packages.
- Windows (and apps) looks/works better, is easier to use and/or has better/more features. (6 votes)
Simply not true. Why? Regarding the look: There are so many nice themes you can choose - for sure you will find one that you find cool. And of course you can choose a totally different desktop or window manager - there are so many around (you get an overview at wikipedia). Just combine the desktop of your choice with the theme of your choice - watch, what people do show on youtube! Finally you can either make your Ubuntu look like Windows XP or Windows 7 - watch this video. - Regarding the features: A standard Windows installation is totally barefoot and poor in relation to a standard Ubuntu installation. There isn't either Office installed by default (if you didn't buy it alltogether with MS Office included). People who find Linux has poor features sometimes think of particulare Windows software not available or running on Linux - that is more related to 2.
Related posts: Popular Ubuntu desktop myths, Implementing effective computer security, Going Linux, Efficient desktop environment.