In a lot of ways, yes. On the other hand, it seems like a hard problem to solve - how do you get honest feedback in situations like this, where you want to use it to both improve things overall and judge your employees/contractors? Maybe you can't.

I guess, at least a small step would be to make it so values less than the highest rating don't count against you so negatively - it should be ok to be a 3/5 or 7/10.