They might well be, but peaceful ones are beside the point really - in World War 2 the majority of Germans were peaceful. Islam is not a peaceful religion; it causes trouble wherever it exists. In essence, for x number of peaceful muslims in your country you have to accept y number of terrorist killings in your country.
Admitting muslims has been this country's biggest ever mistake. Let them to their own countries; East is East etc
Its all very well ranting but you haven't offered any solution -although I can understand your point and the frustration behind it. Certainly the idea that multiculturalism has been a success, is not true and we need to look for different solutions.
In the same way you would argue political correctness has prevents honest discussion and hidden the problems that exist, I would also argue that blaming a whole group of people for a minority of fundamentalists is also preventing honest discussion and it incites hatred.
I don't agree with your argument regarding Islam because Muslims have lived in the UK for many many years, the terrorism is only a recent thing.