I've taken turns at Kingshead...it was fun. I've turned over the whole group to new staffers who have moved in on me in their anxiousness, crewed them, and healed them for a good hour or so. I have no problem sharing with lower levels, questers who need a few hits to fill a quest list, etc. NOT what most of us mean by rep stealers. We know how to share, to crew, to take turns. NOT the problem.
Example of an experience with my idea of a rep stealer: at Tormenta ALONE with lower lvl friend, disabling molusks for him to work on. In comes a lvl 39, makes a beeline past bored molusks, urchinfists, etc., and proceeds to annihilate the one molusk my friend was working on. Does it again. Friend says "can you please not do that." His response, "go somewhere else where you won't get killed," and he continues to attack ONLY THE ONES I DISABLED for my friend. Friend gives up and leaves, he continues to do the same to me (lvl 37 at the time). Crewing him (rejected, by the way) would have resulted in the fantastic bonus of 60 pts + 20% crew bonus instead of the 120-165 I was getting by myself. Yeah!! This is one of my most recent, but by far not my worst or rudest, experiences with what I call a rep stealer ( not literally, ok?).