They really should do a bit more cyclical design on the Jobs where the "right" way of playing feeds the loop.

Tanks mitigating properly and Healers healing or mitigating should get rewarded with flashy DPS skills, likewise their more basic attacks should build up into flashy mitigation and healing abilities.

Doing something like this from the early levels would teach the roles to use their tools to help each other and get tangible rewards for it.