It never feels tangential, and I'm not saying your point isn't a good one! It's just that if you zoom out far enough, it's obviously not the topic, and this sort of subthread has a way of attracting more attention (and therefore upvotes) than discussion that's about the topic and genuinely curious.

Here's my favorite way of explicating that guideline: it's not that these things aren't annoying—they are annoying! That's why people make posts like this and upvote them. It's just that, at a global level, they aren't optimal for what we're, er, optimizing for (https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...). Hence that guideline.