TP/MP as a second, untouched resource in theory allows them to release far more powerful, situational abilities that don't rely on cooldowns to stop them from being OP. The way it stands now though, it's mostly moot even if new skills used them because 1-50 abilities dont touch the second resource.

I actually thought Bards used their second resource very well, Gladiators too. Only difference being that SE hasn't added any super-niche abilities to a class that use the pool. I do really wish they'd take some of the Black Mage abilities (like Freeze) and throw an extra resource on them to increase their potency and lower their cast time.

Hopefully hybrid classes will make better use of the second resource when it comes to stacking job skills ontop of new skills, ontop of basic skills.