So, everyone here ranting about the reqirements seems to not see the whole picture.
Ther requirements are not only for the mentoring site, they are also for the roulette bound to the system.

1k dungeon clears means you have played a lot of time, so you should be experienced in the game.
300 commendations means you are not a complete jerk.

1 out of each role at 60 means multiple things:
- you should be done with leveling in havensward aka you are in the actual content
- you have a proven way to say "I know all the spectrums of the basics of the trinity and the game itself"
- speculation: The roulette will say which role you have to pick to join

It is just a level requirement like all other content in this game.