Yea most weren't, but that first sucker punch although it certainly wasn't some haymaker, could still cause some damage to someone, give them a black eye, knock out teeth, knock them off balance where they hit their head on concrete, etc
Its also the fact that it was premeditated and instigated
You should be able to sit in your seat at a game in a non-violent manner and not have someone swing a punch at you like that, regardless of their strength.. by everyone's reaction, its pretty clear that he was the problem in that entire scenario.. and without some sort of consequence, there isn't as much deterrence to prevent others from behaving the same
I'd hate to have to run a meeting at work on Monday with a big, swollen black eye because some nut job sucker punched me at a Pats game lol