Good lord, let's not take any pages from Facebook, or we'll wind up getting our tastes in niche fetish fiction sold to advertisers and periodically "accidentally" shared with everyone we know against our will.
While I agree that the current rating system is broken, I don't know that an alternate system is going to be much of an improvement; you still have the issue of trolls who decide to just down-vote everything every few months, and it's even less useful for feedback because there isn't even the possibility of intermediate values to reflect quality. I say just abolish it altogether.
