I think that argument may have been valid ten years ago, but IMO distros like Mandriva, Ubuntu, Mepis, PCLinuxOS, Freespire and openSUSE have gone a long way in addressing this. One should be careful to distinguish between ease of use and ingrained product conditioning when assessing this issue. (This is a comment from general experience, and not aimed at Fudzy.)
The other common criticism about hardware support ignores the fact that, to write a device driver, technical info is required from the OEM, and there are some OEMS that simply do not cooperate. Perhaps some don't see the financial upside considering Microsoft's dominant desktop market share. These drivers have to be reverse-engineered, which often results in limited functionality, e.g. wifi cards that work, but not with WPA etc. In these cases at least, one has some options with GNU/Linux, whereas OpenBSD, for example, will not support devices like these because of their more rigorous requirements for device drivers, like future support, and the refusal to wrap binaries for security reasons. The point I'm trying to make is that people are laying the blame at the wrong door in respect of hardware support.
As for the "market share" of GNU/Linux, it is difficult to find business numbers because a license is not required for each copy. If one looks at the explosive growth of open source applications on sourceforge and the new distros coming out on distrowatch, one would be hard pressed to argue that GNU/Linux is on the decline. I think this has also lead to the porting of some great open source apps to Windows and OS X, and I doubt that anybody could argue that this is not good for users.
