The problem with societal and cultural plurality is that everyone pits themselves against the resident or majority group - slowly, the majority get utterly sick of being forced to conform to the demands of what everyone wants according to their arbitrary associations to religions, ethnicities, gender, sexuality, etc., and wants to tell the lot of them to f**k off.
We wanted to bring the world together in a spirit of individualism, but all that's been brought to the UK is tribalism, ethnocentrism and a desire to manufacture self-loathing within the resident population to afford preferential treatment to certain groups. For this reason, I'd quite gladly revert to living in a monolithic and culturally and ethnically homogeneous state which isn't geared around the politics of guilt, shaming and self-loathing. The alternative spurs division, which is exactly what they wanted.