I'm inclined to delete these answers (which are being steadily flagged), and tell the author that the best thing to do in this situation is nothing --- even if it leaves these questions on the unanswered lists.
Does this seem reasonable?
There's previous discussion at Questions answered in a comment. The current batch of answers seem very unfortunate because often the question wasn't precisely answered in the comments, but rather it was explained why it was too vague.
Feel free to use this post to re-discuss this. Personally I don't think it's so bad to have these "answered in the comments" answers, although I suspect that the tiny harm they cause by unnecessary bumps outweighs their tiny benefit.