In review beta the recommend deletion button for an answer shows this screen:
I understand there has been some history and debate about "thank you" and "I'm having this problem, too" comments, and though I looked I may not have read every post on every page about these two topics since they seem very vast. But don't those two options fit within the "This is a comment, not an answer" specification? It seems like if you wanted to you could split this up even further and have options for all kinds of comments that fit into this one category.
For example, why isn't there a fourth option for "This is a question to further diagnose the problem comment, not an answer" and so on? Shouldn't we just have one "comment" option and then be able to add a custom message addressing the particular type of comment?