Here's what I learned as a tank (if anyone cares, probably not):

As long as you do what your role is supposed to do, I'll be happy and won't complain.

DPS: Your job is to kill stuff. I don't care how you go about it, I don't care what rotations you use. Just kill the mob(s) before it kills me.
Healer: You are there to keep me alive. I don't care if you wanna DPS or sit there with your thumb up your butt waiting for someone to take damage, your job is to keep me (and the DPS) alive. Don't care if you Holy spam, or add some DoTs or whatever, just make sure I don't die.

I've had healers who go into "DPS road mode" and actually stay in Cleric Stance so long, they actually forget to heal me and I die. When That happens I'll call them out. Sometimes, I'll pull a group and die right away, either because my gear can't support the number of mobs, or the healer can't keep up (usually both). When that happens, I'll apologize and start pulling smaller groups. I've also had DPS pull out ahead of me and start pulling mobs complaining I'm "too slow". I just let the fool die a couple times. More often than not, the healer is on the same page and let's them rot for a few minutes.

Bottom line: You are in the group for one reason: Tanking, doing dmg, or healing. I don't think wrong to call out someone who is not doing their role. People should not be told how to play. Like others have said, if we get to the end and get our tomes, the party was a success.