No. We already see some mentors using the system simply to gain achievement rewards. We don't need to give another tool for the general player base to abuse.

Mentor said something you don't like? Downvote!
Mentor provided good, but unwanted advice (use straight shot before your dots to help increase your DPS)? Downvote!

Yeah, I don't want to lose my mentor status for actually doing my job- helping people- and being lucky enough to get someone on a bad day and wanting to take it out on me. Western players are entirely too prideful and would rather bring an entire team down than to accept humility and improve.