I see a lot of questions with comments that are in reality answers, and no actual answers. Are people just too polite to "answer" rather than "comment"? It seems that many experienced users will just leave a comment to a question, even though it mostly answers the question. This can make noobies like me somewhat uncomfortable. I can't comment because I don't have the reputation, so I'd rather answer, but there are comments that are an answer already. Am I just confused?
It is always better to leave an answer, if you can provide enough information to make a good answer. Some sites will even delete any attempts to answer in the comments. Here we're a little looser with that rule. Space is hard, and often it takes a lot of little leaps to get to a final answer. As a community we have decided to allow comments that point toward a solution but aren't sufficient to make a good answer. That said, if you do see a comment that would be a good answer in its own right, it is perfectly fine to suggest that the user turn it into an answer. If it gets turned into an answer or someone else incorporates the info into an answer, you can flag the comment for deletion. Also, if you see a pattern of a particular user trying to put actual answers (as opposed to guidance toward a solution) in the comments, you can flag their comments.