That's already available. Turns out, admin moderation is still necessary to make the website tolerable. Besides, boards generally have just 150 threads runnin

That's already available. Turns out, admin moderation is still necessary to make the website tolerable. Besides, boards generally have just 150 threads running at once. If the majority of the live threads are just spammed crap, that makes everything worse. If there are 100 topics with lively discussion and 10 or so spam threads that haven't been culled yet, no problem. If there are 80 spam threads, then there's going to be a ton of churn as everyone competes for the other 70 threads. Each new one bumps another off the site. There'll be discussions started anew, with the same crap filling it up because people think they have to say it every time. This is what happens on fast-moving boards. And one could ask "Why not change the number of live threads? Or never retire threads?" To which I'd respond, "If you have to keep recommending changes to fix what your other changes cause, maybe the original change wasn't good."