I do it some times, write perfect answers as a comment instead of answers or write the answer as an answer but later hide it, because i know how the bandwagon and the herd effect work and is increadible strong here. Some times it doesn't make sense to answer as answers, even if is a perfect answer, even with good or official sources backing up, but we want to help the person with that question anyway and as a comment we have less trouble in doing it. The problem is that many people believe in what they want instead of what is right and he/she will probably make a mess of your answer for low importance unless you prove your point and even if you are able to do so, most people will refuse it because they want to believe that is wrong. So in resume answering as comment allow you to help that person and others with the same doubt seeing that question later, giving it the right answer but also avoiding so many trouble that should'n exist, especially if the answer is right but is not convenient. Maybe in the future if this problem goes away, people will be more sure of letting it as answers instead of comment or hidding it too much.