1: Spam makers can make far more spam than you would think possible. 1a: Spam makers can make far more spam accounts than you would think possible. 2: Moderators handle the grand majority of that spam before you ever even see it in addition to managing admin tasks. 3: I don't want to have to block 300 posts and posters to see 1 that I have any possibility of enjoying. 3a: In the best possible world, AI would handle the majority of that grunt work, but there's no telling how wrong it can go.