There are a large amount of questions that have been answered in the comments section, they are old, usually over 6 months. Usually I just close them out with "in need of moderator intervention" and explain. These might be ~1/3rd of old questions. The user has no intentions of using the system to get their answer. Is this the best way to handle this?
There is no such thing as answered in the comments section. Comments aren't answers. These questions have not been answered.
If these questions have been around for 6 months without answer, then they are dead wood and should be culled. Part of the purpose of this site is to build up a repository of questions with useful answers. Unanswered questions will probably be search hits, but not what the searcher is looking for since there is no answer.
If the answer has negative votes and you have enough rep, you can vote to delete the question. Otherwise, this may be a case where flagging for moderator attention is appropriate. Hopefully a mod can jump in here and clarify what the correct procedure is.
Another option is to answer the question yourself. If you see a "answer" in a comment, understand it, and are capable of expressing it in your own words, then go ahead and write a answer. I do this routinely, as again, answers in comments are no answers at all. Sometimes people will write a quick comment because they didn't have time to write a proper answer, or sometimes insufficient information is available at the time. However, most of the time it seems to me that people are not really sure about the answer, so are afraid to write a real answer that might get downvoted. Again, those aren't real answers, so there is nothing at all wrong with you writing a proper answer saying the same thing. However, you should only do this is you believe you understand the material and believe the answer to be correct.
By writing a real answer, even if largely the same content as a comment, you are helping the site by:
- saying, "yes this is the answer, and I'm sure enough that I'm willing to stake my reputation on it". This is one reason comments aren't answers.
- elaborating on a brief comment. Comments are short. Answers should go into a little more detail or background, although sometimes a comment-length answer is fine. A good answer goes a little above and beyond just answering the question. This might include examples, giving background reasons why, dispelling apparent misconceptions of the OP, etc.