I think KisaiTenshi makes one very good point, though. The healer is responsible for keeping the party alive and if anyone dies or we wipe, we WILL get the blame. (Especially in Cleric, even if the cause is they didn't avoid a telegraph).

Personally, if I'm in any doubt-- the tank is doing things that make me a bit nervous (or DPS for that matter)-- I just stay out of CS. Even if I then look back and think "I could have worked in a triple or quadro holy afterall". At least no one's dead.

The other times I don't really DPS is when I'm really tired. Some times I just got done raiding or doing something, I'm trying to get the EX bonus before I sleep... So I'm just kind of half consciously spot healing where needed and not doing much else.

Lastly, I'll point out that DPSing is a lot easier on SCHs than WHMs. SCHs have the off-GCD, insta-cast lustrate which isn't affected by CS, and CS doesn't nerf the fairy either (unless you summon her with it on).

I won't resent a healer that only heals, though. As long as we're alive. DPSing should be a personal choice, IMO. I do it when I think I can get away with it. Heals first, however. And there are various reasons for one to not play at their peak all the time, especially in laughable content such as EX roulette. Hopefully all that doesn't make me a horrible, inefficient healer :)