Healers are like insurance.

- You have them because you don't know if you ever need them.

- If you never have an accidents (aka party does extremely well), you feel like insurance is an unnecessary waste of money.

- But doesn't change the fact society needs insurance.

If contents is tuned to be punishing on healers even when the party is perfect, than the party who make mistake will never even have a chance.

That's why DPS don't have problem because more DPS = more endorphin = bigger ego, and people like that.

No one really want to pay all that much money into insurance ... until they have an accident and wished they have insurance.