I'm impressed that Jon lasted as long as he did. A new, chaotic environment where you have to form social bonds with backstabbing strangers and do humiliating challenges, while people you can't see watch you 24/7 and pay to make fun of you and play loud noises from the walls is about as stressful a situation as you can create for an autistic person without putting them in actual danger. I'm surprised he didn't ask to leave sooner, and the fact that he stayed for 17 days says a lot about his mental fortitude. He was a funny guy and worthy of respect. Sad but not surprised to see him go.
I'm still enjoying the show though, and I think the immunity voting is a good new direction to take it in.