I recently tried Ubuntu after leaving Linux as my primary OS in 2003. You're wrong. The GUIs are only fine if you're willing to stick with their narrow limitations. I think it's because they're constantly being rewritten instead of incrementally improved.
Examples:
When I hooked up a second display and clicked "detect displays", it did nothing. No error message, no effect. I see no way to fix this without editing config files manually.
My sound doesn't work at all. It's listed properly in all the config screens, but nothing comes out of the speakers. Now what do I do? I see no easy way to try different driver or other things without delving into a kernel module mess. Hello, terminal.
How do I disable that wretched shutdown beep with a GUI? The mute control has no effect on it, nor does disabling the system beep in the sound preferences.
This is basic stuff that's been an issue for 10 years.
Sorry, but desktop Linux in 2009 gave me the same experience as desktop Linux in 2003. I.e. 3 days of googling and sludging through manuals to get things working. The process is a tad smoother now, but it's still only good for two groups: Grandma who'll leave it the way it is, and experts who live Linux. Almost everyone I've ever met falls somewhere in between. It's hard to be just savvy in Linux. It's all or nothing.
Pretty skins are just that, skin deep.
Don't give me that paid support crap. I've never called MS support. I've never called Apple support. I can figure out how to maintain their systems by using them. If I'm going to have pay someone to help me with how to do basic things in Linux then I might as well just buy one of the other two.