I have received several comments from people that don't like the fact that my "accept rate" is very low. Now, the reason being is that I don't "accept" questions as I don't see why my opinion is more important than of those who voted.
What's the point of letting the one who asked the question decide which is The Right Answer? Why is their opinion worth more than anyone else's? Why not let the votes decide which answer is correct?
Update: What I have against these features (the big green tick and especially the accept rate) is that it is too visible to other users. Though I do like to give extra reputation to people that helped me solve my problem.
Update 2: note that most problems have more than one solution. I can accept a suboptimal answer, whereas the voting system gives other users the ability to help making this decision.