My ten year old daughter plays soccer and gets made fun of on occasion for it as it's somehow perceived to be a "sissy" sport. When I was young (I'm 40 now) almost nobody I knew played the sport and though we had a high school team, it was a bit of a joke and nowhere near as competitive as other sports. There are just so many sports that are more developed, more profitable, and more respected culturally.
Soccer has exploded as a youth sport in recent years, but not necessarily at a high level, but more as a recreational thing for kids who aren't interested in the other sports. Rules are simple, not much equipment required, and cheap to play. The coaches around here for youth recreational leagues barely know the rules, haven't played before, and aren't even really fans of the sport. It's most of just a get the kids outside and running around for 6 to 12 year olds. Participation after puberty seems to fall off a cliff.
My daughter is interested in playing for a more competitive team and our town of 30,000 didn't have enough girls interested at U12 to form a team, so we've had to drive 45 minutes into a larger city (200k) to have here try out for a competitive travel club, but she is unlikely to make it as she has only ever played rec league in our small town. The cost to play in the team is about $1,500 per year. And even if she does make the team, it'll mean significant travel (hours each way) just to play in a few tournaments and about 8 to 10 games a season.
So I think the distance between our cities, lack of coaching, no significant club infrastructure outside of large metropolitan areas, cost, time spent traveling, cultural stigma, and competition from other sports that already have robust college and professional infrastructure means we won't see the US become a soccer/football juggernaut anytime soon. Some day maybe...
