There was a guy (can't remember his name) who said that US is the only place where you can put US guys, Mexican, Chinese and ... (whoever) and make them work together. In Europe this is not the case, probably because of historical reasons and as a result of the last 30 years of immigration policy (especially the french-speaking countries).
My other theory is that Europe is left behind US in the technical area. If something is top-notch in USA, it will "come" in mainland Europe in 10 or more years. For e.g. now the MBA is hot trend.
Disclaimer: I've been working remotely for the last 4 years.