Jokes within thoughtful comments have no problem to get upvoted here. Don't mistake "apparent humorless" for "completely dry", as many highly upvoted comments do contain humor, but it's more subtle and within a comment that is insightful even without the joke, not just a comment containing a joke without anything else.

On Reddit there is a lot of jokes, but most of them are replicas or just pure memes that gets repeated ad infinitum, nothing that really cracks me up except some rare ones. But on HN, when there is a highly upvoted comment with a joke somewhere within, it's always good one that contributes to the comments otherwise insightful points.