I've read countless threads about this 'low rating' problem, but no one ever complains about the other problem, overly-inflated ratings... This is just as much a problem, where skinner X get high marks simply because he/she is skinner X, and for no other reason. (maybe skinner x is much loved, or he/she is 'my buddy')
I've also seen people say, "if I don't like the skin, and can only rate it low, I don't rate it at all" If this is your attitude, you shouldn't be rating anything, period. It's not about stroking egos, it's about evaluating skins.
If a skin had a fair number of 'honest' ratings, then the people trying to hurt, or inflate the marks wouldn't matter so much.