Whenever I run a flashpoint as a tank or healer, before we begin I tell the team (if healer) that if dps pulls a mob I wont heal them they can die or leave I dont care there are to many dps'ers in this game. As a healer my main focus is keeping the tank alive. As a tank I will always protect the healer first and maintain my aggro. Dps are expendable.
My main is a healer and this blanket statement is just plain wrong.
Some DPS - yes they are bad agro monsters who need to be told to behave sensibly.
But no DPS can run a flashpoint without taking some damage. In certain flashpoints and ops you will encounter different mechanics such as agro tables resetting during the fight or bosses that cannot be taunted. Will you refuse to heal them?
If I was in a flashpoint with someone with such a blanket bad attitude, I would vote kick you. I have in fact vote kicked a healer with a bad attitude on Kaon under Seige once.
Do not consider yourself above common courtesy and sense just because others depend on you to keep them alive during a game.