I think the problem is that he doesn't understand that just because it can be done, does not mean it will be done.

Sure, you can learn ALL of the trinity's roles by level 30. Good players will typically have a good idea of what's going on before 60. But again, because it can be done, it doesn't mean it will. The large majority of the players will in fact lack this knowledge. The system needs to make sure the mentors have quality, much more than it needs to ensure quantity. Are these requirements weeding out some very good players that unfortunately do not meet the requirements? Yes. But it is also weeding a lot more players that shouldn't be mentors, and that is more important. Remember this system is to HELP the newbies, not to enable the entire player-base some rewards.

Also another thing about your tirade of level 50 vs level 60. They need to ensure jobs are at 60 because of pre-HW/ARR leveled people. I am on a legacy server and I know a LOT of people with all jobs at 50 because they leveled it in 1.0, that have not touched and know very little of the job. Typically they keep these jobs at 50 and only level what they like/want to 60. By ensuring jobs at 60 you know that they had played the job in the past 8 months enough to have it at max level. On the other hand, having the limit be 50 you open the floodgates to people that haven't touched the jobs in four years. Likewise, it lets people that stopped playing since 2.1 and likely have no clue of what the game is now to dispense advice. These are all very bad things, so restricting it to 60 over 50 is the only sensible option.

Also, you seem to have completely skipped the actual physical requirements of performing the mentor service. You seem fixated into helping DRG's as a DRG, and the current system may allow that, but what of helping a PLD as a PLD? Or a WHM as another WHM? When doing the roulette, you'll have to change to another job to help them. I am going to help Tanks personally, and this will most likely be done from my SCH or any of my other DPS's, because I can't help a WAR in dungeons as another WAR/PLD/DRK. Forcing you to have all 3 roles at 60 means you are more likely to be able to fill any role than someone that only has one job at 60.