The Americans don't care as much about the Ryder Cup, that's it in a nutshell. I don't believe the Americans to be better golfers, however. We play in better weather and on easier courses. I've played everywhere and American golf is a bit easier. The greens are designed for higher shots (Back-to-front angle and softer) and generally are in better condition.
The PGA is a joke, they are soooo pampered, play EASY courses (yeah, I said that) and more importantly, travel easier (private jets, etc). Of all the courses I've played the easiest have been PGA tour stops.
Give these pros deep grass bunkers (like the Scottish, etc links) instead of the simple sand bunkers and they'll be 1-2 shots worse a round.