It seems pretty common to hear parents of ASD children talk about a time when someone told them that their child can't or won't be able to do this, or learn that. I come across stories like that all the time. As wrong as I think that is, that has been rarely my experience with my kids, or even myself. As a matter of fact, it's been the opposite.
I don't know how many IEP meetings that have been called by me to discuss services for Bubby. No one has ever said "He can't do it." It's always been "He can if he tried."