Britain has never been anything more than a public toilet for invading tribes. Celts, Romans, Anglos, Saxons, Vikings, Normans, Danes and now mulisms... everyone took their turn. The English identity is basically just the genetic soup of being repeatedly conquered and raped for a thousand years.
And if an island separated by the sea like Britain ended up this mixed and broken, just imagine the European continent... the real genetic landfill. Yes, The very idea of a pure European people,nation and ethnics is nothing but a pathetic fantasy.
So maybe treat immigrants a bit better... after all, You've always been mixing, but why hate Muslims so much?