I'd rather watch soccer, at any level, than to sit through another baseball game or Nascar race.
Yes the NFL and MLB and NBA may be watched and followed by many more people. But when I was in school there wasn't a soccer team, there weren't any soccer players getting recruited to play at college. I don't even pay attention to it still to this day but I know kids that are at college on soccer scholarships. It's just going to take time.