It comes down to culture. HN for example, generally frowns upon humor unless it really is providing some kind of insight into the discussion -- I've called this place the least funny site on the Web and I still mean it.
What gets passed off as 'Internet humor' is not actually funny. It is too stupid to be funny. It is something else. I think this article inadvertently makes this argument. (Some sort of postmodern misappropriation of the idea of humor).
To say that a community or group of people frown upon humor makes me depressed. Humor is a fundamental human coping mechanism. It is how we deal with things that are painful or stressful or otherwise bad.
If the culture here starts claiming that humor is 'frowned upon,' I'm not letting the door hit me in the ass as I leave. Who the fuck wants to be a part of that culture? I'm not a damned robot, I like things that are funny. If it makes me laugh, how will I be frowning?
We've all observed that x website 'went downhill' when people started using 'internet humor'. This isn't the fault of humor in general, heck, it isn't even a causal relationship; it is correlative.
It is just as possible that as the user base expanded, you had a higher quantity of people who could not meaningfully contribute to the debate. One way for these users to interact with everyone else is through stupid memes and lolcatz.
There are plenty of other ways, however, for them to interact with the greater community, and (it seems to me that) these are just as toxic (trolling, flame-baiting, repeating what someone else already said, repeating platitudes or creating various forms of cults of personality and hero worship around the users that actually can contribute meaningfully).
So please, 'frown upon' humor that contributes to a low level of discourse. Burn it to the ground. But don't resort to a slippery slope argument against all humor, and don't turn a blind eye to behaviors that are just as bad.
I don't quite know the answer to this which is partly why the essay remains unfinished. But I do want to note that the upvote/downvote mechanism happens to be especially vulnerable to pathological humorous behaviors. A small, concerted clique of the "wrong element" can radically change the tenor of the site compared to a large and silent majority and, once the shift is made, the trend becomes self-reinforcing.
All it takes is a couple of redditors coming over and unthinkingly upvoting the humorous answers to start a mass movement.
Trolls only have an outsized influence to the extent that the rest of the community has fuzzy or differing ideas about community norms. The larger the community the more likely this becomes. Trolls work by flirting with the boundaries of acceptability.
Crafting a joke that fits all that is probably worth an upvote just on principle.
IRL, due to the kind of conversation that goes on around here, HN would be akin to the floor of the NYSE on a bad day. Lots of shop talk, not much else. It's all rather sad in a way, but it does keep the content of the site focused. We constantly have meta-discussions here as a defense to keep the conversational content high and there seems to be a community consent that humor, in general, is not for HN.
Part of the problem is that what often passes for Internet humor is absurdism. I'm not sure if that's because it's the clearest type of humor you can get across in text while being clear that, "hey, this is humor hint hint" since irony and sarcasm are so easily misconstrued in text, or some other effect. But it seems that once a site allows for acceptance of absurdism as part of the dialogue, the information content of the comments seems to drop quickly to near zero. It just introduces so much noise you have to find signal in, and it makes having a high signal conversation so much harder. I find it sad on many levels that HN is such a fun free place, but I get why it is that way.