I'd separate use cases. If you want to talk to/about yourself or if you just want to rant at somebody, post memes, etc then Twitter is easy and natural to use. If you want to have meaningful nuanced conversation, Twitter is useless. So you end up with a dichotomy where for some people Twitter is a fine fit and for others it's completely unusable. Both are correct.
I'm actually a Twitter user, and I think this is a very jaundiced opinion. I have a lot of different interests and following people on Twitter is a very good grapevine system. Math twitter is a good place, for example. A lot of people are very enthusiastic about how it has enriched their mathematical diet. There are many good people on Twitter who use it for serious sharing of ideas in other fields as well.
In general, it's a good way for people to share thoughts and links to a diverse audience. Liking Twitter isn't a sign of foolishness. Among the social networks, it's not as gross and corporate as FB, or as superficial as Instagram.
Your dismissal of the reasons why people might like Twitter, the implicit claim that it's useless for sophisticated people like yourself, and the apparent desire to impose black and white dichotomies on the world risks making you into a candidate for the category of "just wanting to rant at somebody".
We know that HN has its own serious cultural problems, after all.
