HN has a culture of pointing out that obvious, boring jokes have no place here. There's a constant struggle by people to introduce them, but (amongst others) those of us who watched Slashdot flush itself down the toilet of shitty humor are going to police the site because it's what we want.
Isn't it fair to say that the field of computer science has (up until recently, apparently) distinguished itself with its corny humor, dorkiness, and resulting sense of humility? I feel like puns and bad jokes had generally been a special part of the culture of early technologists. It's a little sad to see that give way to a kind of self-important seriousness.
Don't be sad. The one context doesn't really apply to the other because these communities are so different in size and cohesion.
It isn't a question of humor, but of stock humor, which grows like crabgrass on the internet and quickly takes over. I think scott_s got it right years ago: https://news.ycombinator.com/item?id=7609289. Humor that clears the signal/noise threshold does fine here.