In the commercial software world, user interfaces are generally designed by one group. Linux is different. Linux lets people create what they want. You're in control!
What's really interesting to me is the theme that has come out as of late in these debates about usability, and it really comes down to two things: do you want simplicity, or customizability?
Keep it Simple Stupid
Another way to characterize desktop environments (or DEs) that are striving for simplicity is this: get out the way and let the user do their thing.