The competition in the Nationwide Tour is tremendous. By the time these guys earn their card by finishing top 15 or getting a battlefied promotion (3 wins in a season) they are really pretty much primed for PGA play...that hasn't always been the case...this tour has matured since it was called the Hogan Tour. Europe has no Nationwide Tour equivalent. Also I think Tiger has inspired more young Americans than young Europeans to take up the game early.
Europeans play much more match and team play than Americans...with the exception of El Tigre, the best match players are found on the European Tour, imo.
For the life of me I have no answer as to why Europeans don't dominate more on links-style courses.

Shade