Interesting that our fans of both teams sit mixed in with each other. If they did that for European soccer, there would be endless fights and riots. I've gone to games with friends that are fans of the other team. In some places in Europe, someone would never be friends with someone that didn't cheer for their team. A lot of them take their tribalism way too far.
I won't paint with a broad brush to say everyone here is more civilized than Europeans, we have some crazies, and they have some reasonable folks. But I am personally far more civilized than someone that can't sit with or even be friends with someone that cheers for the rival team. I'm a Sens fan, and my 2 oldest best friends are Leaf and Hab fans. Maybe more of us have the levity to realize there is more to life than sports, and it's supposed to be fun, not hateful. I couldn't imagine hating someone because of what sports teams they cheer for.
Although I have been to a few NFL games. I've seen crazy drunken insanity boorishness in Buffalo to friendly family atmosphere in Cincinnati. Places like Buffalo and Philly are insane, while Cincinnati and Detroit were relatively friendly.
Alcohol intake is a huge factor.