"as designed", due to the gradual decrease in Twitter's functionality due to unknown reasons (probably trying to manipulate people into signing up to boost user count and ad revenue)

Because AI models kept trying to train on twitter for free.

Okay, Elon (jk).

AI models for... spam bots? There are way better sources for human writing. Is this a reasoning Melon Husk gave for closing off the so-called "town square"? Pretty poor reason, if so.

Twitter requires an account for anything more than a single tweet nowadays. There’s a link with an unrolled thread in the comments here.

It's been that way for a little while. I presume it's a compromise between requiring a log-in and full "guest" access.