While it's a cool idea, it's useless just for the same reason that rating other users is useless. For everyone person that will post a bad rep for no reason (or misguided reasons), you'll have someone else posting a positive rep for equally wrong reasons. Additionally, if it's based upon one rep per person, then that's even more wrong, because moderators act over time, not just one time per user. That alone makes it inherently flawed.