Soccer fans are weird.
They really aren't! How many of us watched Battlestar Galactica and couldn't wait for the next episode every week? How many of us are now enjoying watching game of thrones? HOw many of us enjoy playing video games because of the story that they tell? Everybody loves drama.
How many people go to rock concerts every single time? It's not just because of the band playing, it's that sense of community. It's the pure adrenaline you get from being part of a crowd that is rocking on in the middle of the night, jumping around, singing along with the band. It's raw emotion shared amongst a group of people that is larger then can be reasonably considered natural.
Football (and indeed all sports) combine(s) those two, and more: Not only is there drama, but it's happening in realtime! There is community, but also a shared sense of pride and indeed everything is simply bigger then any rock concert can be. There really is nothing weird about going fully wild about that.