I only used Romeo as an example because it is obvious you are a Browns fan. Obviously it didn't cost Bill his job, he has won 3 Super Bowls. My point is there are a lot more Romeo's than there are Bill's coaching in the NFL.
Edit, I see blumj covered this while I was typing this post.
You are right, Belichick knew he would get punished somehow and he did. But now he has mark on his record. Belichick can only guess how much worse the penalty will be if he does it again. For the sake of the discussion you'd have to assume further infractions will only generate a harsher response from the league.