Quote Originally Posted by Lemuria View Post
And the big one, a player who has played DPS, Healer and Tank has not only played three jobs, but a wide range of jobs. Know why? Because a successful player has gained cross-class skills from a variety of jobs, and will understand which skills benefit most.
This is a leap in logic. There's no requirement on which classes they need to 60 other than 1 of each role. DPS classes in particular might need Invigorate and Blood for Blood from LNC, Second Wind from PGL, and Raging/Quelling Strikes from ARC. Much less healers find great use in Swiftcast from THM. None of these skills are really required by any content listed as pre-reqs for being a mentor, so to assume a player has it isn't logical. They SHOULD have it, but there's no method to ensure they do and no real challenge that would force them to do so.

The rest of your argument was sound, but there's just no proof or requirement that Mentors grabbed the cross class skills they should have grabbed.