/(PS I wouldn't have wanted to live in Europe or the fledgling US a few hundred years ago when our Christian tolerance was less well-developed than it is now).//
The "pack" (at least this member of it) attacks "the extreme examples of Sharia or the Islamic faith", Allen, but also notes that in countries like the Islamic Republics of Iran and of Pakistan (not to mention Saudi Arabia)many of the "extreme examples" are fairly mainstream. It further notes that Muslim majority countries which forty years ago would have been cited as modern, secular and democratic (Indonesia, Malaysia and Turkey among others) have all, under political pressure, made accommodations to some of the "extreme" elements of Sharia. There have been few Islamic countries in the modern era which haven't had sizeable Islamist movements (remember Morsi and the Muslim Brotherhood in the Arab Spring?). So recent history suggests that the Muslim world is moving in the opposite direction to the Christian world of the last five centuries, i.e. in the direction of more dogma rather than less.
The important question to me, then, is this: "What proportion of the rapidly increasing Muslim populations of Europe shares these Islamist sympathies?". The answer to that question doesn't have to be "Most of them". (Neither is it the same question as "How many want run us down with trucks?", although that question is neither irrelevant nor trivial. The answer to that question could be "None at all" without affecting the point I'm trying to make, or, I suspect, the point behind the OP.) The question equates to "How many want Western societies to become less Western and more Islamic?". Even a relatively small activist minority can have an influence disproportionate to its size. There's an example in the (partially) foiled Trojan Horse affair in Birmingham, you'll recall. An activist minority may also coerce and intimidate a passive majority. (Remember the mayor of Tower Hamlets?).
You might look at the success that has been achieved so far. These are cases when Muslim sensibilities are accommodated at the expense of non-Muslim, and cases where special dispensations are made to Muslims which are denied others. Simple examples: removal of pork from schools, time off for prayer and exemption from hygiene rules in hospitals.
But the biggest triumph of the activists has been the censorship of of the mainstream media: where did you see the Charlie Hebdo, or the Danish cartoons?