That being said, it may have been that you were siting near an unusually high concentration of bad fans. 

Confronting them can be fun.  The majority of the time they will apologize and be surprised that everyone doesn't think exactly like them.  Some of the time they will sullenly apologize (kind of) by will limit their bad fandom to muttered comments instead of screams.  A few will generally try and ignore you, but at least you made them aware and at least moderately uncomfortable.  On rare  occasions you will get one who is beligerent and will step up their bad fandom yelling.  Then you either have to ignore it, or you can have fun by being loud and super positive whenever they are loud and rude or negative.  That can be fun and can get those fans around you laughing.

There is a difference between bad fans and passionate fans (though there can be passionate bad fans).

Bad fans jeer and deride.  They scream insults at refs, players, and coaches.  They basically do all in their power to make sure that they and all those around them have miserable experience. 

Good passionate fans can also be very loud, but their loudness is cheering on their team, particularly when they are on D and when good plays are made.  They don't boo refs or the opposing team.  They certainly don't boo their own team.  When they disagree with a call or decision, they don't scream at the few, coach, or player.  They may discuss it with those in their party though.