I trully believe that the main reason is uncontrolled illegal migration, that will soon blow up the UK ( both in the ordinary and figurative sense) just like France and Belgium, if the measures aren't taken. Nation is fed up with it. That's why so many people voted for Brexit
I think you should've quoted AlexTu, because it was his question at the first place ;-) And I don't go along with the idea that videos are time consuming, everybody has a 3G Internet nowadays, it's super fast :-)