It's a mixed bag really, as a White Mage main I usually don't dps unless I know the fight at hand intimately.

As a Pld and dps, I have had some healers go bonkers with dps even to the point that as a tank, I die, because they forgot about cleric stance and didn't heal me enough. that makes me angry tbh.

Very few healers I've come across that can actually balance good party health and decent dps at the same time. So, it's down to the particular player tbh, if you're basing it on duty finder parties, you'll never know much, is healing there main job? or a 2nd or 3rd? do they work at it and practise? or don't they. Most healers I've seen recently suck royally and I'm talking at Lvl55+ well beyond the point they should have a decent grasp on what they're job/class is capable of but again it's just people.