I play a healer because it is by far the most interesting for me. Your job is to keep everyone alive. Especially the tanks. Without you no one advances and you can take care of yourself better than most classes. If someone is being a jerk to you, well stop healing them if you wish. On top of making sure everyone is ok you can also sneak in damage here and there when the opportunity rises. You don't have to just sit there spamming cure all day long. Make the fights interesting for yourself, but don't put you or your party in jeopardy. You are protected by the other classes and they'll come to your defense the moment you are in trouble. Think of everyone as your own personal body guards. Hehe.

I used to play dps classes, but I made the switch to healers and I doubt I will ever go back again.