When I'm healing, my primary focus is keeping tank/others alive. It's not my preference to DPS at all, I'd rather people be getting hit like crazy and I have to be on my A game to keep everyone topped up... but that being said, if I'm in a situation where there is a lull in people taking damage (I just landed a huge crit adlo, boss is doing some move that has a stupid long cast time, etc) or there is a DPS check and the dedicated DPS just isn't quite cutting it, I'll throw up Cleric Stance and try to put out.

If my DPSing is putting the group in jeopardy, it's not worth it. If someone complains about it but the content is still getting cleared, they can stuff it. On the contrary, if someone wants to complain about a healer DPSing and the party is still alive, they can stuff it too. If there is a problem with people dying, or DPS checks not being passed because of the healer focusing too much on DPS or not DPSing at all, then maybe it's worth a complaint. Otherwise, deal with it.

Only one thing to remember with healing... party health is primary, DPS is secondary. OP seems to be taking care of the primary, so there's no problem doing the secondary.