From reading the comments, I can tell that most of us think the current rating system would work if used correctly. I agree. That won't make people change their ways. Mine included.
Here's an idea: have a simple popularity vote, sort of like Facebook, except I would add a dislike feature. So, X number of people like this piece, and Y number of people don't like it.
With a popularity vote, hate rating wouldn't matter, wouldn't make much of a difference. If someone went through and disliked every piece he/she could find, it would only add one person that dislikes the piece, which wouldn't effect the number of people that like it. And, the ratio wouldn't be skewed.
So, for example, if 12 people voted for a piece's popularity with 10 voting that they liked it and two voting that they didn't like it, the piece would have a popularity of 83 percent. One more person couldn't drop the popularity like a bad rating can. The worse thing that another dislike vote would do is bring the popularity down to about 76%. Plus, more 'Like' votes would bring it back up.
Then, with the actual ratings, make it more difficult to leave a rating. Require comments, for example. Or, split it up into categories so that real support can be gleamed from it.
All right. What do you think about this one?