>Which itself proves that if Linux would come preinstalled on one half of desktops (the less expensive half), and Windows/OSX on the other half, most of the people would chose Linux desktops and stay with them
I thought that too at one time, but it simply can't be true.
As you use your computer day-by-day, month-by-month, try to think about all the things you do without thinking. I mean things like subconsciously learning that if you do certain things, something crashes or the computer grinds to a halt.
Or things like upgrading your distribution and needing a simple one-line fix to get something working again. Or getting new hardware and needing to spend even just a few minutes Googling for how to get it to work.
For most of us here these obstacles are insignificant. We don't really even notice that we need to spend five minutes now-and-then fixing things, because it's so easy.
But consider the perspective of someone who actually *can't* do those things. That's not a five-minute interruption in exchange for new cool versions of software; it's a complete inability to do something you used to be able to, in exchange for...nothing.
When was the last time Ubuntu made a new release that didn't require you to a) learn a new way of interacting with your computer, b) fix something that broke, or c) both of the above? I've tried every Ubuntu release, at least very briefly. All of them. And one of those things has happened *every* *single* *time*. It's not only on release upgrades even. My partner uses Ubuntu and has learned not to accept new release upgrades so long as the current release is still supported, because of the inevitable breakage, but periodically a high-priority update comes along and her printer will stop working; fortunately she's usually able to solve it with some Googling, because countless other people had exactly the same problem and managed to figure out the magical incantation to fix it.
Back to those things you learn to subconsciously ignore: try actively looking for minor bugs - the kind of things they're calling 'paper cuts'. When you start paying attention, you start to realise that you encounter *dozens* every day. Around the KDE 4.2 time (IIRC) I actually wrote down a list of all the minor bugs I experienced within the first 5 minutes. It wasn't a small list. I filed bugs for some of them; others had already been reported. In some cases there was some flaming about worrying over small things, but *small things add up*.
Here's an example: http://dl.dropbox.com/u/4957647/calendar.png
What's gone wrong with the rendering there? No idea. I'd have to start with a fresh KDE profile, then start bisecting all my configuration changes to find out. And what's the point, when more little problems like that will appear with the next dist-upgrade?
By the way, the red 'fail' icon in that shot is because so far I've only spent about 45 minutes trying to work out how to get wireless networking to work. It only took me a couple of minutes to get wired networking working because I have enough Debian experience to know that I needed to add 'auto eth0 inet dhcp' to /etc/network/interfaces. Good luck figuring that out if you're a new user. Why doesn't wired networking work out-of-the-box on a default install of the last two Ubuntu releases? No idea, but that's exactly the kind of thing I've come to expect (to be fair, in many cases the network connection does work; it just refuses to perform any name resolution - to a non-technnical user that's the same thing).
A solution that's permanently 90% finished is not 90% as good; that last 10% is utterly crucial for a good user experience.