I'd be fine with leveling the normal way (as opposed to a crystarium/grid/board), but I do wish you had to level them.

Right now, each class only has one job. But in theory, that will change.

So by unlocking WHM and taking your CNJ's level to 50 as a WHM, you have CNJ50. Later in the game, SE introduces Elementalist, and after doing 5 quests, you're 50 ELE as well. Then, SE throws Green Mage into the mix. 5 more quests and you're at max level.

I feel like these are distinct jobs that we should have to level somehow.