An incentive would certainly be welcome. But really, as trite and cliche as the saying "helping is it's own reward" is, it kind of stands in MMOs, and I really wish more people agreed. MMOs are, fundamentally, a waste of time. Don't get me wrong, I love playing them, but as of right now (yes with the advent of legalized RMT this may change), there are absolutely no redeeming values to playing an MMO. It's just something you do to entertain yourself and have fun when you're not doing something else.

What makes one way of wasting time any better or worse than another, if both are fun? Everyone has to define for themselves what makes the game fun for them. Even given that, there are so many reasons repeating content can be fun beyond getting a tangible reward: being with friends, the fight itself is fun, the thrill of the challenge.

A tangible reward for helping out would be nice, but I don't think it should be necessary.