I think part of the appeal for many is that life has become so complicated, so a simple bike is appealing because it's simpler than what we've become used to. So it's an aesthetic choice more than a practical one, for some people.

I bought a cheapo generic Chinese fixie bike from Nashbar in the fall. The frame and geometry happen to give a very nice ride. I ride this bike for fun. It will never be my main ride. And since I spent so little on it, it doesn't have to be.