The Muslimification of London and much of Europe in general may be part of it, but most of it is that people in that part of the world don't like some "Ugly American" barging into their countries, criticizing them and their leaders and telling them what to do. To many, he is an obnoxious, rude, crude bully and they don't like it or him. I don't care if this is all part of his act and this is how he makes deals. It's just plain wrong.
I sure hope he behaved himself with the Queen.