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.
Then I regret to inform you that you are playing TOR wrong.
I am a healer main. I also have a tank as my second most played character. There is literally no way to keep DPS from pulling agro SOMETIMES, because of how the threat mechanics work. Now, if the DPS is being totally stupid and running amok, that is one thing. But during a fight, the DPS are SUPPOSED to be fighting the mobs that the tank can't hit solo. They'll take damage then. So you're going to, what, refuse to heal them because they're playing their classes correctly?
Your mindset works in WoW where if the tank loses agro it means they're doing something wrong, or the DPS pulled mobs the tank wasn't fighting. It doesn't work in TOR, sorry.
I'd vote kick you from the group for having that attitude, tbh. Healers are expendable too when they have a bad attitude.