If you have specific workflow where the golden path is suboptimal, sure. But I would not think that average user has any preferences and for many users Gnome is very reasonable.
Id second this. I used to lose a lot of productivity via desktop tweaking, and have now converted to sticking with gnome defaults (as people have said, gnome really does "stay out of your way").
hypercustomization is cool, and I like that KDE gives hobbyist something to experiment with.
I think in the long term though, KDE and gnome need to solidify. Something gnome-like for the base user, and then a layer of customization on top of it for the KDE hobbyists (with successful experiments integrated into the gnome-layer).
I'm all for diversity of desktop environments, but there needs to be a common core (especially since linux is driven by open source development)
