Earlier quoted context omitted.
Running the risk of being an armchair psychologist, I think it's pretty well established that RMS likely falls somewhere on the autism spectrum, or at least has some sort of behavioral condition that leads to behavior like this, as well as his documented social quirks. Which is to say that I think he's probably mentally stable, but a bit strange by everyday standards.
But punching himself in the head? I knew Stallman was weird as we all did and that yeah, he's probably got some disorder but when he's punching himself in the head publicly you can't help but wonder if maybe we should reevaluate our faith in his ideas. Having a mental disorder does not automatically invalidate anything he's ever promoted or done but for me personally, I'd ask myself whether the next idea he promotes…
I'm not sure with whom or where you hang out, but I'd say Stallman is one of the most controversial figures in the world of software. Even people who mostly agree with his viewpoints often say he takes it too far.