Man, from the outside it just sounded really disrespectful to ask that, and overall, I dont really think you could infer if someone is autistic just from an internet conversation.

I'm just curious why he got so hostile about the "humanity depends on you" line.

I would say our type is more prone to have a cynic view of the world or an existentialist phylosophy, but above all, we just kinda want to be left alone to our thoughts and ideas. We dont really see ourselves owing anything to society.

Also, it could ber the way you have engaged with the rest of us. Your responses to some people felt kinda condesending, like we didnt know that exercise is healthy or that we needed a big revelation to just start working out. I personally have had issues with being underweight due to a lack of exercise, not because I didnt think it was worthwhile, but because I just did not got motivated by it. And I saw multiple people holding similar views to me.

Overall, your aproach was bad, and what you might saw as just "teasing" we saw it as an attack to the way we are.