Of course, the United States men's national team has never been good.
Jim, to answer your question, soccer is a sport with a lot of tension in it. It is the only sport that attracts the world and, as you said, raging violence as proclaimed above. But if you actually get to watching it, it's not a bad sport at all. It's actually one of the most fun games to watch.
Anyway, not an excuse, just an explanation from my view.
Why does soccer attract so much violence from the fans? These battles don't end up like those in the ANDY CAPP cartoons, but often serious injuries and fatalities occur. I really do hope that men's soccer never becomes popular in the U.S.A.