Fridge Logic: Rethinking all the qualities about Jon in this way makes you better understand why the marriage fell apart; he was a laid-back New Yorker, was 20 when he got married, was independent, was 22 when they had the twins, and by then, did NOT want any MORE kids. How come no one saw the doom on the horizon when the show started?!
Especially when you figure in the fact that he was married to a control-freak who sees nothing wrong with abusing other people publically when they "disappoint" her. (And we're not just talking about Jon here).