The claim that Autistic people have "no empathy" may be understood (and has been used) as a way to see them as less than fully human.
Baron-Cohen links autism to psychopathy, in which "empathy deficits" lead to acts of cruelty or violence. This despite the fact that autistic people are more likely to be victims of violence than perpetrators of violence. (His theory of empathy is more complex than this, but what gets coverage is the gist of it.)
This kind of characterization of Autistic people is only one part of a larger problem of understanding and (dare I say it) empathy. When a homicidal parent kills an autistic child (happens a couple of times a year in the US), the press often demonizes the child as "impossible" to live with or care for, lacking all loving reciprocity-- thus implicitly justifying the parent's actions.
Yes. It just isn't wise to oversimplify human beings-- reductionism, particularly when it comes to any disabling condition, is dehumanizing.
