Super general statement here, but whenever I ski in the North America whether it is back in VT or Colorado or Whistler, the general run of skiers in North American are better skiers than the general run of skiers in Europe. This is because almost EVERYONE in Europe is a skier or has skied, just like almost EVERYONE in the USA plays or has played basketball. Skiing is totally mainstream in Europe and is far less of a core thing, so you're naturally going to see people who really don't care that much about skiing going skiing. In North America, the general skiing population is more at an enthusiast level rather than a mainstream level. And because it is more enthusiast based, you are going to see more interweb interaction among its members.
This is not to say that North Americans are better skiers, just that the average mix is different. Also, the general skiing population of North America could really care less about racing, whereas in Europe racing is king. The images of racing are what really motivate skiers in Europe, whereas it is more the images of freesking (freeride & freestyle) that motivate skiers in North America. Almost all of the resort ads I see in Europe showcase perfectly groomed pistes and people in tight clothing ripping around on 70mm skis with sunglasses and no helmet. Whereas, even on the east coast of the USA, resorts try to emphasize powder and some element of freeskiing into their marketing.
The third part of that is that there are French freeski sites for French speakers, German sites for German speakers, and so on. So like Doug said, some decent European traffic is here but the participation is not and I think a lot of that has to do with language barriers and the fear of making a mistake in front of the core, vastly English-speaking world of NS.