Ask a random NT dumbfuck in the street. Will s/he be able to give a reasonably good explanation of what AS is? Most probably not.
No, they won't.
But most don't come up with Volkert van der Graaf or a schoolkilling.
They do have either the image of a severely autistic person, or of a computer wizzkid without social skills. The latter the most in my experience. Still flawed, but not as negative as you make it to be.
Lots of people do know someone with a kid on the spectrum too nowadays. That does make a bit of a difference in how they see things.