As someone who mains healers, it drives me up a wall when I see a healer pull aggro and run away from the tank. If you pull a few enemies away, chances are high they won't do nearly enough damage to kill you right away. Heck, outside of a handful of special attacks, they shouldn't even be doing enough damage to make you panic. Just run up to the tank and heal yourself. Problem solved. It's obviously still bad when dps run away too, but it irks me way more when I see healers do it.

Speaking of running away, guys, we need to talk: don't run away from the healer in frontlines and then complain when you die. I have six other people I need to look out for, seven if i include myself, and I'm not going to worry about some special snowflake when the rest of the team are getting their faces smashed in.