The mentor system has been flawed from the get-go. The icon next to your name is being used as a status symbol and most mentors are more interested in ultra-fast clears on the roulette so they can get achievements, rewards (glamour pieces, titles and mount). It's not rare to encounter impatient and rude mentors even on the mentor roulette.

Becoming a mentor is just another automated mechanic which unlocks more stuff for your character. Attaining or keeping the status doesn't require you to do anything and while rewarding people who are willing to go the extra mile to help fellow players is a noble idea, the way the rewards have been implemented doesn't reward helpfulness, but grinding and fast clear rates.

Becoming a mentor shouldn't be tied to some achievements, but rather to being eager to help inexperienced players. Having grind-y and unique rewards do not fit the program. Misbehaving mentors should be punished harder, as they should act as an example to newer players.