The reason you have seen emotion the last two weeks is because the players are competing for a chance to win a HS state championship. Don't you see the same emotion during club season when the players are playing in state cup events? You've never seen emotion when the club team wins/loses in the tournament finals? I know it's been my experience...on both sides
Of course, you also have to consider the added emotions of senior players that realize this may be their last game. Underclass players are also dealing with emotions of providing the seniors one more shot...or falling short.
No doubt that HS soccer is more emotional, but I've seen my share of tears on the club fields as well.