It's linux. There's so many ways of customizing this and that, people can go out and figure that out for themselves. Toss in a highly polished UI, people complain about resource usage. In all honesty, I really only see Mac users having a huge beef with the UI. "ZOMG IT'S NOT AS PRETTY." Seriously, wut? Those who put such huge emphasis on such pointless things are the same people who go, "OMFG A MAC RUNS JUST LIKE HOW A COMPUTER SHOULD RUN!" These being the same people who barely know how to go on the net, make a few word documents, add a picture here and there, play with a webcam (and think they're highly tech savvy for doing so) etc.
Seriously if people want flashy, they're the people spending big bucks on either a Mac, or a spiffy piece of hardware (namely Sony, Voodoo etc.)