Suggesting that players should stop using certain moves once they score a certain amount of goals is insane, partiuclarly since slides and scissors are pretty basic. I have no problem with soccer teams scoring as many goals as they can or being happy about it or using trick moves to accomplish it and that has nothing to do with my support of the US team.
If it was a friendly or a game when goal differential didn't matter, I would feel differently, but that isn't the case.