Can you point to some specific guidelines used to judge low-quality vs high-quality jokes for HN purposes? Or are we suppose to go by your personal and subjective opinion of low-quality vs high-quality comedy material?
In this case it seems pretty clear. If you're not sure you could try reading more posts before posting. You should be able to pick up the general vibe/tone.
I found the comment funny. Since the purpose of a joke is to be funny this makes it high quality as far as I am concerned. If you didn't find it funny, I guess you would consider it low quality. The point is that judging comedy and jokes is so subjective and personal as to make any such rule regarding quality a joke itself. You can ban all jokes or mandate that jokes can't contain racist, sexist, ageist, or other such potentially offensive content but trying to filter jokes based upon quality is a bit ridiculous.
AFAIK there aren't specific guidelines but posts like the grandparent are normally moderated down. (https://news.ycombinator.com/item?id=2965166) is an example of well-received humor; it's one of the top rated posts.