While it is true that most players who make these claims are lying, you have to admit that there is a problem with the system when players who are woefully bad at the game can get the crown.
You're going from zero to one hundred with this. SE can make getting the crown more challenging without bringing savage into the equation. For example players could have to pass a far more advanced version of the novice hall that syncs you down to certain stats (so you can't cheese it with gear) in order to gain the crown. And have it legitimately challenging. Dps checks, needing to interrupt spells, being unable to survive without cd use, etc.
As for the backlash I say tough poop if you're not good enough to get the crown. It means you're not skilled enough to teach.
I would like mentors to at least be average to good at the game, and the requirements to achieve the crown should reflect that. One of the worst players I ever met in my 15+ years of playing mmos got a mentor crown with ease. This should not be happening.
If you mean that they should be welcoming to questions when they have the crown on, then yes. If you don't want people to bother you with questions then take off the crown.
If you mean that they should know absolutely everything, then no. No one knows everything. This is unreasonable to expect.
If it's a minor thing I personally say nothing. Some people get their knickers in a twist for such small things that happened once and could have been a misclick. In my opinion if something isn't causing much of a problem, it's unsolicited instruction. If it's causing players to start carrying, then something needs to be said.
Of course some people think any advice at any time is unsolicited even if they're causing wipes. You can't please everyone.
However I must add that how a lot of people give advice is frankly superbly rude. Anyone who gives advice in this manner deserves the same thrown back at them.
"Good" in this context is up to the viewer. In my books someone who is new to content and doesn't make the same mistake more than twice is good. To others making any mistake means you're bad regardless of whether you're new or not. The latter is woefully unreasonable. No one is perfect on their first try.
I expect this but what I consider to be good is someone who is at least average in their performance and is polite. I don't think I'm unreasonable to expect a mentor to have a decent grasp of their rotation and not do things like blow all their defensive cds before running for several seconds to a trash pack if they're a tank.
If someone expects good to be on savage level, they're being ridiculous. Savage requires more than to just be merely good, assuming you're not getting carried.
No, mentors are there to guide. Not babysit.
The stereotype exists because even the worst players can get the crown, and sadly it tends to attract players who have an inflated ego because they want something that clearly marks them as being a skilled player. It is not the playerbase's fault that this stereotype exists. It's SE's, because they made getting the crown far too easy.