It's more of a slur filter than a profanity filter. People can say fuck and shit and ass and the like, but slurs that dehumanize certain groups of people are a no go. In your case, it involves an ableist slur for dehumanizing people with intellectual disabilities. Other words that get caught in the filter include the N word, the F slur for dehumanizing homosexuals, b*tch and c*nt which people consider misogynist for some reason, and some others that escape me at the moment.
The fact that your speaking a different language shows why most people think the slur filter is dumb af.
That's good to know.
I was just pointing out cunt of all words shouldn't be banned in Aus, How many cu in the NT stickers do you see on cars? They're pretty common here in Brissy.