It's the mass Stockholm syndrome the government gave us with a steady diet of propaganda and pure grade idiocy. Most of us fell for it, a lot of us were born into it, and now we see it for what it is after their carefully crafted web of illusions starts to unravel. It takes time to deprogram an entire country of the matrix we've been in, hell I'd argue the whole world to an extent

There’s also an element of class warfare among the native Britons. The upper classes think they have more resources, education, and connections to withstand the invasion so they show off their fitness a la the Handicap principle at the expense of the lower class native Britons who are on the street level with the invaders. The high class are too racist to feel threatened by the brown invaders, but the high class are threatened by lower class whites who may only be lower class because of circumstance and not genetics. So the high class figure that while they have the upper hand, they’ll handicap everyone via invasion and they’ll survive it better than their rivals who are currently in difficult situations.