Perfectly simple: for some years ago, it was considered to be perfectly OK to spank a child that wouldn't listen to his parents. Many autistic kids have problems following overly verbal instructions so they won't do what they're told. Is it right to spank a kid that isn't able to follow your instructions?
Or consider an autie kid having a public meltdown. Would you spank that kid? Lots of parents would because they don't know better.
autistic children, it is said, have a high pain threshhold.
what stupid parents to continue to spank a child, as punishment, when the child barely responds to that stimuli.
restrict them from their special interest.
see how common sense parenting works?