People express their prejudices carefully these days. Sexism and racism and supposedly taboo Jokes about physical handicaps are condemned as tasteless.
Nobody shuns cancer patients any more.
But people with mental illness are still fair game. When John du Pont was arrested on murder charges, TV comedians exploited his mental illness for a few laughs. It's easy to make fun of. But it's apparently not so easy to understand. Mockery, discrimination and stigma persist despite scientific research showing mental illnesses to be as real and as serious as any other sickness.