That's not really how it goes. I've noticed that, unless someone has played a healer class before, they really don't do anything to make our jobs easier. I've had runs where DPS would stand in AoE's AND DoTs, tanks would make massive pulls and use no CDs, etc. The same players often run outside of healing range and bring their AoEs and tethers to me. It's the inconsiderate players that we'll sometimes let die, sometimes for our own good, not players that "don't do their jobs" well. I personally don't care how low your DPS is or how squishy my tank is; so long as they do their part in staying alive and not creating chaos by ignore mechanics, we're fine.