I recall 1.0 not having any jobs and anyone could learn any ability. Sounds nice right?

Now think about balancing any sort content around this anarchy. WHM that can spam flare? sure. PLD with a DRG jump? Go for it! It would be effectively impossible in the long run. I've heard some say this system was one of the big things that hurt 1.0 outside of the terrible story and clunky menus.