There is a lot of this in Washington D.C., too, but the opposite way - Cowboys fans in Redskins territory trying to piss off local Redskins fans. There is also the race factor because way back in the day the Cowboys were one of the first teams to racially integrate while the Redskins were among the last, and so many African-Americans in D.C. began a tradition of rooting for Dallas in order to piss off the hometown populace.
That must have made 1987 pretty weird.
An Alabama fan killed large trees near the Auburn campus where fans celebrate . He put poison in the ground Then he admitted it by calling a radio show. He spent 76 days in jail for that.
Growing up I had a casual interest in basketball. I played a bit on the playground and occasionally watched Magic and the Lakers whenever they had a game televised in my area and that was pretty much it. Then one day moms came home with tickets to the first 2 rounds of the NCAA tournament in Richmond, VA.
OH.MY.GOD.
To this day I have had very few entertainment experiences that even come close to what I experienced over that weekend. The energy, the excitement, the suspense, the drama. Jumping up and cheering wildly when someone pulls off a flashy move, standing up and screaming “DEFENSE” at the top of my lungs in unison with 10k+ people, the collective silence that descends when someone takes a (potential) game winning shot and the sheer madness that erupts if the shot goes in. After that weekend I literally couldn’t get enough basketball in my life and I have been a die hard fan every since.
It’s like watching a great movie that is being written and acted out live on stage while you sit, watch and (most importantly) react as demonstrably as you are comfortable with.
My suggestion, go out and grab some tickets to any game of any sport close to you that might be competitive matchup and just go experience the feeling. Don’t concern yourself with rooting interest, just go and try to feel the energy and see if you are entertained. If the spirit doesn’t move you then try another game/sport/whatever until you find one you like.
This. The only time I care about sports is when I’m betting on them.
Football is especially fun to bet on also.
It’s not always about parents. My dad really isn’t into sports, and my mother follows the Steelers and the Pirates, but she’s not really a fanatic. HER parents on the other hand, hooboy. 
I didn’t really get into sports until I was in college and I think now most Dopers will tell you I spend a LOT of time here in the Game Room. And even before that though, I wanted my hometown to win because well, it’s my HOME. It’s kind of a community thing. I remember when I was in 7th grade and the Penguins won the Stanley Cup and then won it again the next year and me and my classmates were just bouncing off of the walls about it. It was a lot of fun singing along with “We Are the Champions” on the radio, and talking about the games at school.
No matter how indifferent to sports you were, if you lived in Pittsburgh in the 1990s, you knew the names of Mario Lemieux and Jaromir Jagr. (Jagr is the only person on earth who can make a mullet look good)
It’s all about that common bond, the one thing everyone has in common is that you’re all from the same hometown, and you’re ALL Pittsburgh. Age, sex, race, it really doesn’t matter – the only colors are Black and Gold. So that’s a big part of it.
So yeah, in one way it’s “just a game”, but it brings people together, nonetheless. And it’s FUN. It’s exciting. And on the practical side, it brings quite a bit of revenue to the city as well. (Plus many of our sports figures here have do a LOT for the community – Mario Lemieux, the Rooney family, etc)
Besides, there are a lot of things that are “just a whatever”. Plenty of people get really invested in things that when you get right down to it, don’t really matter in the long run, but are still important to them. I’m guessing you have interests or hobbies that others find boring, or stupid?
It doesn’t sound like they’re being antagonizing, it sounds like they’re being sensible.
I was there and it didn’t.
“It’s a topsy-turvy world, [generic sports fan], and maybe the problems of [a sports team] don’t amount to a hill of beans, but this is OUR hill, and these are OUR beans.”
- The Naked Gun…(well kinda)