We do have some good soccer players as well, but we have some major holes that prevent is from getting results against better teams, primarily on the defensive side. We really only have 1 defender that I would call "good" and goalkeeper position is a complete disaster. We saw it last night as Belgium really didn't have to work hard for any of their goals.
The underdog teams that are getting results against or are at least putting a scare into superior opponents do it with elite defense and then perhaps stealing a goal on the counter or a set piece. That's how the US did it also back in an era where they occasionally picked off a giant. This new attack oriented USMNT is more entertaining to watch and will probably generate more consistent results against lesser opponents, but it's tougher to beat better teams that way.