Attacking the source rather than the content is usually the mark of a poor debating position. If the content is good, the source doesn't matter. If the content is bad, the source's badness will be self-evident.
A debate is a formal event with rules. These are Internet comments. I'm not debating a position. I'm expressing myself. If you think my observation is nonconstructive, that's fine, but it's not because if I were debating I would have made a blunder, it's because we have different expectations and desires in this conversation.