If an article is truly inaccessible or illegible, then it shouldn't be on HN. But if it's readable-albeit-with-annoyances, then it belongs here if (and only if) the content is sufficiently interesting, irrespective of annoyances. In that case we want the comments to focus on the interesting content.
Not that annoyances aren't annoying—they are, and they annoy us too. But the cost of having comments about them is much higher than the benefit, especially because they're so repetitive. Annoyance comments also tend to get stuck at the top of the thread, accumulating upvotes and choking out more interesting discussion.