I personally believe it's because they replicated the same incentive structure as Twitter. Being provocative generates engagement, which gets you reach and creates the perception of relevance.
At first, people were just happy to be at an alternative to Elon Twitter. But good vibes only get you so far when the incentives point the other direction.
It's insufferable, yes. Even though I'm a left-liberal, it feels foreign to me. Twitter is worse at the limit (endless neo-Nazis and Maoists) but at least I feel some diversity while I'm there. Bluesky is so uniform in the annoyingness of its community.
