Hi.
I've never understood where people get the funny in this.
Some people need to feel superiority over everyone else, be that a "lower" animal or another human.
Making fun of/at someone or something who's supposedly on a lower ladder of evolution or different in any way, is generally considered funny. IMLE 90% of mainstream comedies draw at least some of their material from that.
Oppression by words is even taught to be more "humane" or "more acceptable" than a physical oppression. "A word is mightier than a sword" and crap like that.
There's one flaw in that logic though IME. The majority of mentally handicapped just don't care. Somehow they're incapable of being sad or infuriated over something that someone says. I'd consider that as a blessing.
Oh, they obviously do get sad and infuriated for different -perhaps illogical to us- reasons, but calling names and joking about them just doesn't seem to sink in.
That leads to another reason people tend to joke about mentally handicapped, because if someone doesn't respond at all, that's considered to be a valid permission to do so.
Is the stuff mentally handicapped persons do, funny?
Yes, majority of it IMHO is.
Would I rent/go to see a movie that makes fun of mentally handicapped?
No.
Do I laugh at the jokes in movies and in everyday life?
Sometimes, perhaps 30% of the time.
Would I crack such jokes?
NEVER.
Regards
Sam