Yes, to some degree, it is because the Americans don't buy into the team concept as easily.
But, this year's European Ryder Cup team was very strong. This time, it was the U.S. team that had players you couldn't believe were there--Wetterich, Taylor, Henry, etc. Some of the U.S. rookies played well, but, going into the Ryder Cup, every member of the European team was more accomplished than them. The bottom half of the European team was much stronger than the bottom half of the U.S. team. Of course, it was a guy near the top of the U.S. team--Mickelson--who let them down the most. He was awful--maybe the worst of all 24 players. So, Europe was a solid favorite this week and it wasn't just the Americans' inability to play team golf.