This and mentalities like it are the best case I can make to answer your question:
noraina, you may have difficulty being British or French or Canadian and Muslim at the same time if your adherence to Islam comes before your identity and loyalty to your nation. There can be a conflict. Serenity's example and hypocrisy (wanting non-muslims to respect muslims and benign muslim behaviour they are not comfortable with, while disrespecting and denying rights to the homosexual and transgendered due to Islamic beliefs) shows why I wouldn't want mass immigration of Muslims of his sort to Canada. Unfortunately we can't screen everybody (and expect honest answers) as they apply to immigrate, so blanket rules applying to all muslims may start to gain an air or reasonableness.... and people like Donald Trump then twist and exagerate to the point of wanting to ban all muslims. I would not ban all muslims, but I do wish to maintain the moral and societal progress my country has made, and there is a real conflict between the current British/French/Canadian values and Islamic values.
Imagine if Saudi Arabia was a democracy. Would you not be alarmed if millions of Christians or Atheists (or nudists) moved there, with very different and un-islamic or anti-islamic views? This is the same reason that Israel has (and the only legitimate reason, amongst a dozen illegitimate reasons) for not integrating Palestinians into one joined democratic country.