So, we have Threads, well-known for lack of moderation for open transphobia, sexism, homophobia, racism and other bigotries that people would *much rather not have boosted into their timeline and by the time they've blocked, they've already seen it and it's too late*.
THIS is why Threads is being pre-emptively blocked, and not because it's a "Satanic Panic" or "leftist moral panic", as I've seen it termed in one thread.
It's self-care and self-protection.