Earlier quoted context omitted.
I found my interest in sports went up when I understood the rules a bit more deeply, and some of the reason why. For instance, basketball for a long time looked really silly to me, and I thought I knew the rules because "we had played some in gym class", but it turns out that I knew almost nothing about it. There's a lot more to the rules about who can be where, and a lot of rules around what your feet are doing and…
Same with the rules, especially for basketball. However, this just made all basketball games interesting to me. To this day, I really cannot empathize with "having a team." I get that it comes off as neckbeardy or holier than thou, but it just seems like arbitrary tribalism - maybe because I moved around a lot as a kid(from BIG SPORT cities, too! Green Bay to Houston to San Francisco), but I never really understood w…
Major sporting organizations (MLB, NFL, NBA, NHL, etc...) are very good at selling stories of players/teams and having people emotionally connect with players/teams at that level. This is what leads to favorite players which can lead to favorite teams.
Another aspect is region. For example, I've grown up in Seattle since I was a toddler. Everyone around me is a Seahawks fan. I am a Seahawks fan. It'd be too much to follow multiple teams for me, but some do.
This gives me something in common with those around me, and having team spirit and dressing up on Sundays is fun. Hanging out with friends on Sundays, watching football, and shooting the shit is a lot of fun and sometimes the only time we can all make to see each other as we get older and our lives drift in their different directions. That bit was a little off tangent but it does help illustrate why someone may like sports.
I'll agree that learning the rules really helps. When you're watching two different teams line up against each other, attempting to read what the other team is trying to do and executing against it in real time is exhilarating! There are several aspects of the game that have to be accounted for on every single play. It's a mental, physical, and emotional game.
Hope this helps you (or any reader) understand why someone may enjoy to watch sports. Go Hawks! :)