I'm bit 50-50 on this subject.

While I personally DPS as much I can on healer regardless of content (i don't do savage though). And encourage people do it too.

But

I don't think every healer should be -forced- into it (especially if they not comfortable with it or unsure) unless we talk about said savage and endgame content. In normal-casual content such as Roulette's, it a nice bonus but hardly a deal breaker for the other 3 people to kill the boss.

Again, should be encouraged but never forced or being harassed for not doing it except in certain scenarios.