My most souring experience on SO was posting a comment below an answer pointing out that it did not answer the question and merely repeated it. The comment was

My most souring experience on SO was posting a comment below an answer pointing out that it did not answer the question and merely repeated it. The comment was deleted, and deleted again when I posted it again. Then the author of the answer went on meta and complained about my behavior, from which came a barrage of downvotes on my answer. Now think which answer has 4 times as many votes as his answer, years later? Mine. But why delete the comment? Why not just reply? I don't get it. It wasn't even a mod, it was just someone with 3k points, much less than I have.