Other than that I like the minimalism. I even think the lack of automatically quoting the parent comment is a good thing, as it forces the user to think about the part of the parent they want to quote instead of wholesale quoting it all as the lazy option. If auto-quoting existed the comments would be 40% quotes of each other, and much harder to read.
But apparently there's people who dislike wrapping code so much, that it's worth messing up the layout of a whole discussion even if only one comment has code in it (or by accident, even). Personally, I dislike horizontal scrolling much stronger (and I actually mildly prefer wrapping code, but that's taste, the horizontal scrolling is a big annoyance).
Exactly
You typically see users working this around with spacing, and (sometimes) other users complaining (rightfully) that they can't see the full text on mobile without scrolling.
This is exacerbated by the fact that then HN rendering only has the "<p>" concept, not the "<br>". If one works this around using the greater than symbol, and there are several entries, it blends too much with user-typed text.
It's not a very big deal, but it's pretty much standard feature in forum engines, and the lack of it makes the text outlook unnecessarily worse.