The way i see it, subjobs in FF11 were the "specs" in that game. In FF14, the skills we set from other classes is how we "spec" in this game.

I don't see a purpose in a skill tree system in this game. I'd rather expand on the multi-class possibilities that we are used to both in this game, and in previous final fantasy games.

However, I wouldn't mind a tiny bit of specialization such as what we got with merits in FF11.