The problem is not autistic hand flapping. The problem is when the decision has been made that hand flapping is annoying or weird, and not natural (and adorable!).
I’m angry about the sudden popularity of fidget spinners, but probably not for the reasons you think. I’m not mad that they’re disruptive in class, or obnoxiously trendy. I’m furious because of what they reveal about societal power structures, and the pathologizing of disabled people by non-disabled persons.