I have been struggling to identify why I dismiss Stallman and think of him as a idiot, and your post calls it out: the bullying. The assumption that if you don't 100% agree with him, you are an idiot. And the complete lack of empathy.
What is he actually achieving there? People can legally take his picture without his permission. People can take his picture (on a Facebook-less phone) and then upload it to Facebook later. And what sort of malicious things is the Facebook server going to do with his sacred visage anyway?
So a fan asks for a picture, he demands to search through their phone first, probably gives them some anti-Facebook lecture if their apps don't pass muster... but for no actual "privacy" benefit? Okay. It's just bullying.