If we go back to the early years of the Mosconi Cup as well as World Team Billiards, the USA players (as a whole team) have always not performed well. But, in the early years, the rest of the world other than the Philippines sucked ass. The first World Team Billiards event, the USA top Hall of Famers (and candidates) didn't make it out of their North American region. The "Puerto Rican" Team (made up mostly of Contiguous States USA players that have Latin blood-lines) beat Team America (a Dream Team of players).
It's clear that the loose flowing style that has defined American cueing action excels in long races (as people have said) and needs to be good right from the get-go in short races.
Are the Euro players better? In these short races, absolutely. With leaders like Niels, Mika, and Darren who take every shot with full focus and structured skill, they've shown to be consistent out of the gate in every tournament short or long. That type of focus is hard not try not to emulate if they're your teammates.
Are the American players better? Once the flow gets fully rolling, certainly Shane is better than anyone in the field. And Bergman and Hall: I'd take them in long races as well. And that's the trick. These tournaments (and other short format) are prevalent now, so if the American players can't get into fully rolling flow immediately, their games don't seem to be made for the short races. They need to get rolling. It's the sprint vs marathon idea, I guess. Others have said this enough.
Is this a knock on either side? Absolutely not. This format is what it is.
So who is to blame? There's no blame. The Euros have proven to be better at this format. That's not blame; that's truth.