That's probably a good idea, since it's basically a value that can be made to be whatever members want it to be.  It's not eBay, where the value of a transaction is known, and most feedback left on bitcointalk is probably not from doing deals anyway.  Eliminating that field isn't going to do any harm, and it'll probably do some good.  And frankly I don't think anybody cares about it if they even see the value when looking at someone's trust.