(Disclaimer: the following is a massive overgeneralization, but it does explain why percentages in things like hijab wearing around here are radically different from the ones over there). As you may know, a number of Western-European countries imported guest workers from Morocco, Turkey, Algeria and a few other Muslim countries back in the sixties - and needless to say, the ones who came weren't the most economically or socially successful ones in their home countries, nor the most progressive ones, coming from the most part from highly conservative mountain villages. The guest worker programs stopped fast enough, but the workers did stay and brought over their families, and they have kept encouraging their children and grandchildren to marry people from the same villages or regions they came from. And being close-knit minorities in not necessarily tolerant or welcoming host countries, their natural reflex of redoubling on their cultural identity didn't help matters. The result is that these communities have not only remained far more conservative in all sorts of domains than the autochthonous Europeans they live amongst, but also far more conservative than those who live in the cities of Turkey, Morocco etc. (As a sidenote, such liberal Turks from Istanbul or other major cities, probably also Moroccans or Algerians but I haven't personally experienced that, can sometimes be so very harsh about the conservative Turkish Europeans that it shocks native Europeans, who would rightly expect to be accused of racism for being half as critical.) In Istanbul, or at least some neighbourhoods of Istanbul, you will see see a much lower percentage of Muslim women wearing headscarves than in Brussels or Antwerp - small Turkish villages might still be a different story.
North-America, meanwhile, saw a quite different group of immigrants from Muslim countries for extremely simple economic reasons: whereas the cost of emigrating to Western Europe is very low for families from the Middle East or North Africa, the emigration to the US or Canada requires far more capital, and there's less of a community to support you there when you do arrive. No wonder that the immigrants you got were on average more highly educated and more likely to be progressive. In addition, the common practice here in Europe of returning to the mother country every summer holidays, often for a month or even two, is impracticable for all but the very richest in North-America, and as a consequence the odds of convincing your children to choose brides or grooms from your country of origin are slim indeed, as the ties connecting them to your home country are much weaker. Add to that the general tendency of the US and Canada to be more "melting pot" and much better at integrating people into society in a positive way, and it's really very logical that the situation is entirely different.
So while I obviously entirely support Muslim women who don't wear headscarves, and am annoyed every time I see a converted Muslim woman who feels the need to prove her conversion by wearing a headscarf, and personally would be quite happy if all Muslim women in the world took off their headscarves tomorrow of their own volition, I do also defend the right of Muslim women to choose to wear one, and their right to be judged on who they are and what they say or do instead of merely what they wear on their head. A "simple" headscarf, yes - in communities where headscarves are still so common, there may be many battles that are more worth fighting than that one.
In France, as you probably know being as well-informed as you are, they had a debate a couple months back about imposing a ban on universities against headscarves. I happened to be in France at the time and heard a radio debate about it - it's not often that I find myself in wholehearted agreement with spokesmen for the Islamic organizations of Western-European countries, but when the guy in that radio debate requested that the French government "foute la paix aux étudiantes", that struck me as the most sensible statement from the entire debate.
Yeah. Europe is different.