I have seen several instances of questions which have at least one complete answer, but none of which are accepted, and no comments have been made to indicate why the user has not accepted an answer. Sometimes this is because the user asked one question and never returned after getting the answer they were looking for. However, there are instances where the user is still active, just with a low acceptance rate.
In this situation, is it rude to comment on such a question, asking the user to accept one of the answers, or edit the question to indicate what they feel is missing?