You can “smack an autistic kid” all you want, but it doesn’t help the child. Ever. It never, ever will. Usually, these types of children end up dying instead.
I am so sad when autistic kids are born into abusive, science-denying households. Thankfully, it doesn’t happen that often, because parents look for answers and adapt. Those with a shred of human decency and humility, that is.
Don't the parents object to that after a while?
It will be interesting to see what happens when today's large number of autistic kids become tomorrow's autistic adults. How many of them will engage in behavior that is indistinguishable from an imminent threat of death or grave bodily harm to others? What will happen to them when they engage in such behavior?