Its not pointless.

I like the system as it is now, I like being able to go on Gla and do AOE Dmg and self heal and stuff, i feel more Paladin like than being a Paladin without Cure and such.

I also like being able to opt as Thaumaturge to Raise/heal which BLM Lacks.

I dont believe there is much diversity between them, as the differences in most scenarios dont work, but in the scenario they said,where job = group, class = solo, it works perfectly. Although i wouldnt solo as conjurer over whm lol. Whm gets lucky and has the best subclasses XD (maybe exclusing thm mp thingy)