I think if it's on Show HN, there's an implicit assumption that one is interested in the question "what's the most critical feedback, right or wrong, I can get?

I think if it's on Show HN, there's an implicit assumption that one is interested in the question "what's the most critical feedback, right or wrong, I can get?" JS and load time commenters represent a particular demographic within HN which may not necessarily represent mainstream opinion, so no need to get worked up over them. Just recognize them for what they are, mentally filter them out, and move on to other more insightful comments.