You que as a healer so your main job is to heal.
If you want to DPS so badly, que as a DPS.
They had every right to kick you.

Yes Tamtara is an easy dungeon, but I was running it a few days ago as a level 50 tank but with all the level sync, I still need healing.
My white mage thought "hur dur im gonna spam cleric stance" and at on point I almost died because I was down to about 1% hp from him not healing me.
So yes, that protect actually saved me (along with the 1 cool down I could actually use).

If you don't want to do your job, and you act rude when people point this fact out, don't be surprised that they kick you.

(Although I've seen a few healers like you and instead of arguing I just cast protect and stoneskin myself as a paladin.)