Honestly, I hate how people always have to tag on "by a mentor!" in their posts about getting kicked.

The mentor system is not the problem. The problem is bad players using mentor system. You would've still been kicked because bad players abusing a system for a prize are bad.

Honestly the requirements should be changed from what it is to something akin to a peer review. If someone applies for mentor, after the end of a non-premade party, a random member of the group (maybe also requiring different servers just in case) may occasionally get a "how helpful was this person to your group? popup. They have to meet a certain requirement to be accepted into the mentor system. They then have to maintain a certain ranking from future groups that would still get a popup for them, or else get removed from it. Of course, to deal with people that troll the ranking and vote 0 for everytime, they should have a couple days to make it back up.

Make the mount reward based on keeping a very high ranking (like if a five-star scale, make them have to maintain a 4.5 or higher rank) for X number of mentor roulette.

See how many people can still get the mount.