I don't know why, but maybe because it's the community itself or the layout and how it's changing the mood atmosphere, but I don't see much of friendly and amusing posts around.
Hubski aims to be much more in depth than your normal low-fi, easily digestible posts. I also think there are 10,000 sites out there that provide that type of content and are much more established. In fact, what used to be reputable or semi-reputable news sources have fallen victim to clickbaity and low-brow shit. If that is what you are after, then go to those sites. I think we'd all prefer to keep Hubski the place you go to for content and discussions you can't find on every other site. That said, we do have our own little sense of humor. #nosharesjustsmiles is one example. #ironicbadging is another.
There was a blog post a while back (may? June?) that they were seeing spikes in users and traffic, and that was causing slowdowns on Imgur. I bet the new iOS and Android apps are boosting traffic as well. Last year they got $40 million in new VC capital to expand the server farm to get caught up with the increase.
I think it has a lot to do with what the creators of hubski set out to do. 9 gag is also a consequence of its creator's goals. There are all kinds of other examples that are in between, or further out, than these examples, but the hubski "vision" seems to be based on dialogue. I don't think that necessarily precludes levity, or however you want to put it, but "light/funny" is at least harder to bring out when the emphasis is quality dialogue.