That’d be a problem if people were using blanket statements, but that’s not how the comment is worded.

If someone said, “Autistic people tend to have strong, specific interests,” nobody would be getting insulted. We’d be like, “Yeah, that tracks.” Even if somebody autistic lacked that particular trait, the phrase “tend to” allows for exceptions to the statement - it’d be understood that not every autistic individual fits that description, but many often do.

Which is why it’s interesting that when an autistic person flips that exact same sentiment around to show what “normal” people look like from their perspective, neurotypicals are taken aback.