I personally think a happy medium can be found. The idea of pre-constructed class templates seems like a good idea to me. It's been mentioned a little bit on this thread already I know.

They could add them in as quests you could perform after you reach a certain rank (20 or 25 maybe). If you want to unlock a Paladin template you go out and do the quest and on completion you now have access to a load out that gives you a pre-made ability set suitable for a Paladin as well as exclusive passive bonuses to promote the play style. You could even elaborate on a system like this and add in over Paladin template variants to unlock in game later on as the level cap gets raised and new abilities get added in.

There are of course a lot of "what if's" with this idea. Should you be able to tweak and alter the load outs to your liking while still keeping the passive bonuses? Would these load outs be accessible across all classes? Would you need to have the abilities on the template already unlocked from other classes first? Or would they be abilities exclusive to the template that no class would normally have?

It's a lot to work out. But I think a system like this would not only give classes more direction and uniqueness. But also encourage people to start trying to mix, match, and test abilities in new ways they may never of considered before.