Honestly and bluntly I look at socer as the sport that overprotective parents want their kids to play so they don't get hurt playing a sport like football. Its my opinion and my opinion only that this is leading to the pussification of kids these days. Like I said its just my opinion.
The problem with keeping kids in soccer so they don't get hurt is the fact that the most gruesome sports injury I've ever seen came on the pitch. I saw this clip on the network up at Iowa State while I was there, so for all I know it's still circulating around up there. Guy had possession of the ball and was dribbling up the pitch when another guy comes in for a sliding tackle. He misses the ball and instead kicks the guy in the shin while he's running full steam. Running guy's shin bones snap in half and you can see the lower shin/ankle/foot flop. The most disgusting injury I've ever seen (granted, it occurred during a European pro league game, so completely different level, but it nullifies the argument that serious injuries don't happen in soccer).
Bottom line - I don't plan on telling any of my kids what sports they can or can't play in with the exception of sports that will be too expensive for them to play (unfortunately, it will probably leave hockey and auto racing off the list), or any other activity for that matter. You want to play baseball, football, soccer, basketball? Great, I'll be in the backyard/park playing with you. Dance, gymnastics, acting? I'm coming to recitals, meets, and practices (if that doesn't make them look like too big of a dork to their friends). Wanna be a band geek? They're going to teach me to play their instrument as well. Computer nerd? You're going to teach me how to program. Basically, my wife and I have promised each other that we're not going to tell our kids what they can and can't do. As long as they're making their grades in school, they're going to have our full support.