Following are a few quotes from their FAQ that made my Friday:
"Isn't filtering stupidity elitist?"
"Yes. Yes, it is. That's sort of the whole point."
"Won't people just try to defeat the filter, the way spammers try to get around spam filtering?"
"we think it's reasonable to count on the laziness of the stupidest commenters not to do this."
"Do you really expect to be able to detect and filter anything that's conceivably stupid?"
"a sufficiently advanced AI would probably filter out the whole of human discourse, which isn't the idea."
"What about ironic uses of "stupid" diction?"
"However, we consider the StupidFilter's irony-ignorance to be a feature, insofar as even if an allegedly smart person makes a short, stupid comment, their smartness doesn't make the comment any less stupid. If your mom had designed the StupidFilter, she might say "If you can't say anything smart, don't say anything at all.""