Well... nobody is perfect and Gnome guys have lots of room for improvement too.

But again... Quality of your UI software isn't everything. Sometimes a game-changing feature appears out of nowhere. Apple's multi-touch has changed how I use computer dramatically. And it has almost nothing to do with the software itself: it's a driver+hardware combination that I personally find impossible to live without. OSX allows me to do a lot with just one hand, so I can hold a cup of coffee in another: flip pages, zoom in/out, scroll up/down, etc. This was enough for me to stick to OSX for my daily non-programming computing needs. I even started reading books in PDF format, something I previously could believe I could do.