It's the mere-exposure effect, perhaps. Remember Swing Out Sister?
http://fbcdn.tunewiki.com/artist/med...22/7431226.jpg
The singer actually looks much better without bangs, but when we're used to something, we usually aren't turned off by it. There's an art deco aspect with the hairstyle, too, which might appeal to some people. It kind of says "chic" and "intelligent." On a purely aesthetic level, the shine helps.