I'd note that the author specifically points out that labeling people with mental illnesses as less of a person can have negative effects, and should not be done without good reason. He also does not necessarily claim that people should be treated poorly for a lack of personhood, anymore than one has a right to treat a child badly. He falls short in describing these relations, in no small part due to his overall perspective.
I disagree with where the fellow starts the whole question. Personae or masks are not simply social tools - masks are roles we take on for ourselves even when we are alone. Therefore, the focus on socialization and normalization as the first goal skews the whole business.
There's a whole set of totally personal aesthetic considerations that go into developing a set of masks for a person, which determine who we are, or at least who we think ourselves to be. Oscar Wilde has some brilliant lines about this in his essay, The Decay of Lying, which in turn greatly help to clarify some of Nietzsche's similar thoughts.
"Scientifically speaking, the basis of life-- the energy of life, as Aristotle would call it--is simply the desire for expression, and Art is always presenting various forms through which this expression can be attained. Life seizes on them and uses them, even if they be to her own hurt....Think of what we owe to the imitation of Christ, of what we owe to the imitation of Caesar."
Assuming that Aspies, by sharing certain social proclivities, would also have harmonious aesthetic preferences, leads to the amusing notion that a group of ten Aspies would get along famously. To the contrary, our similarities in certain regards, not having been designed as a social type but rather a personal one, would likely come into rather noticeable conflict. Ten Christs would get on perfectly well, but throw ten Caesars into a room and you'd have a bloodbath on your hands.