So why not make Praetorium contain a pre-requisite for your job stone and nothing else throughout the game? It would be easy enough for the game to identify whether or not a soul stone is in the slot.

It's a small gesture but it could ensure that players have all of their abilities.

I do agree with the OP, there are people who never think about returning to their job trainer on a regular basis. It's bad enough that healers don't have Swiftcast or that tanks don't have all of their defense boosts. For the players who cry out "DON'T HOLD MY HAND" -- it's not, it's a pre-requisitie, you already have it. This would force players to be cognizant of what they're missing and reduce the "GIT GUD" atmosphere. Will it kill it completely? No. But at least we'll know they can do more than L15 moves.