My girlfriend uses Windows frequently at work, and as an experiment I stuck her in front of a Windows 8 machine and watched her use it (she hated it and found it hard to use, but that's kinda irrelevant). Then, for kicks, I stuck her in front of a vanilla Fedora 16 install - she just picked it up and got on with it. The only thing she didn't get was virtual desktops, probably because there is no equivalent in the windows world and it's not very discoverable. So yeh, they could do some work on that.
The point is that it's a good desktop and novices pick it up without much hassle - indeed, with less hassle than other desktops. If you managed to learn KDE you've got the capacity to learn another DE. If you can't use it because you refuse to change how you do things, well good luck to you. Never update, never buy a new car, keep your old mobile phone..