[Jack_]

Because many British (or Canadian, or wherever else) dual nationals from those seven countries were subject to the original ban. One of our most successful athletes - born in Somalia but whom lives in the States and travels for training and meets - would fall foul of the policy. As would one of the MPs in Theresa May's government. That's why.

Not to mention the fact the US is one of, if not the most powerful country on planet earth. Much of your politics has a knock on effect on the lives of people around the world, for good or bad, so people are well within their rights to take an interest in and protest certain policies as and when they see fit.