I've only had an issue with one PUG healer, was quite awhile ago. She was obviously new, and was spamming AOE heals like mad every pull. After the third set, I simply asked her to ease up on the AOE heals. She replied that healing is hard. I replied "I know, just do your best ". The next pull was a little easier for me to manage, and the rest of the instance was a cakewalk.

Some people want to help, and some are just looking for a reason to rant. Many just plain don't know how the game works.

All any of us can do is filter out the useful input, and let the rest sail past as useless babble. Complaining or feeding the rage won't help anyone do either.