If you're pulling as a healer, you are indeed being a prick to your team. (If intentionally, at least. There are accidental pulls from bad positioning)

It's the tanks job to grab the enemies and keep them on him / her. If they aren't comfortable with big pulls (for whatever reason) then they shouldn't be forced to pull more than they are comfortable with. That only causes issues that people will certainly make vocal. But on the other side of the proverbial coin, a tank should never pull more than the healer can deal with, as a stressed out healer is a very dangerous thing to deal with. You can't "solo" a dungeon. You need to work together and pissing each other off is not going to make it go any faster.

This can all be avoided by simply asking at the start of ANY Dungeon, how comfortable the tank / healer is with big or small pulls. Or rather, if they're willing to give it a shot. Be considerate. It's another person on the other side of the screen, not an AI. Treat them how you wish to be treated.

If you are bored playing a healer, don't take it out on your team. It's not their fault you aren't as engaged as you may like.