It's probably because we're all nerds.
In the USA at least, sports companies receive millions of dollars in subsidies, so maybe that's part of it.
For me personally, I don't mind if people watch sports, even if I don't particularly care for them. In regards to the "cheering for your team" thing, I was watching a game from the World Cup, Mexico vs Croatia, (I live in Mexico) and I did find it a little unsporting that they would cheer like crazy when Mexico got a goal, but there wasn't even a clap when Croatia scored their goal. It was a good one too.
Yeah - one of the big downsides to professional sports is their constant stadium-building and renovating that sticks taxpayers with a large chunk of the bill. That's total BS. Once the state is abolished, though, we won't have to worry about that problem.
But why would Mexicans cheer for a Croatian goal? That would be crazy!
Yes. Haha. I wasn't expecting much, just a little clap in appreciation of the sportsmanship.
You have really high expectations!
Hahaha apparently. After Mexico won, everyone went out into street, drinking beer in an intersection. People would walk up to me and say "Hey! You are Croatia!" and then a crowd would gather, and say "eeeeeeeeeeEEEEEEEEEEEEEEEEEEH! PUTO!" That's how people express their excitement in Mexico I guess.