To the OP, whenever a DPS whines about you not doing enough dps, just tell them to stop being bad. If they keep whining at you about it, vote kick that special snowflake for harassment.

Given how dumb tanks are and how lazy I've seen some DPS players in pugs can be, I've learned to never expect healers to do damage. Yes, it's nice and things die faster if the healer gets bored enough, but it should never be perceived as a requirement. Players need to learn that, especially now that so much damage output has been shifted from healers onto DPS and tanks.