Well, he tells non-autistic people to make lemonade, specifically. Guess who the "lemons" are in this metaphor.
Popular fiction both shapes and reflects cultural attitudes. In a previous post, I picked apart the film Adam and expressed concern over the film's troubling conclusion that people with Asperger syndrome—and by extension all autists, since Asperger's is thought of as a "mild form of autism"—are simultaneously too childlike and too threatening to maintain healthy romantic relationships.
This is a reflection of the attitude that pervades Tony Attwood's A Complete Guide to Asperger's Syndrome, a popular nonfiction book that often serves as an introductory text to Asperger syndrome for lay readers.