I don’t think that being able to clear everything in the game should be a requirement. Someone may be able to explain every mechanic in mandatory dungeons but be unable to explain a savage fight, that doesn’t make them unhelpful.

That being said, if there were to be a change, personally I think the only thing that could be done is to perhaps add a separate “mentor commendation” system where party members can commend a mentor. I think a system like that would be better for getting rewards because then those who pick up the status for said rewards have to at least be somewhat helpful to get them.

Again though, being a mentor is more about just wanting to help, like people have said. You’ll always have good and bad mentors, just like in any community.