>>2817832Specific cultures and civilizations have opposing and conflicting values. European traditions made the West great, but European traditions and incompatible with Arab traditions, which can be seen with how the Middle-East is tearing itself apart constantly and their refugees are fleeing to the West and trying to turn the West into the Middle-East.
Subsaharan African are incompatible with Western culture, look at Rhodesia then versus Zimbabwe now.
Specific ethnicities are naturally inclined to collectively gravitate to their own views of how the world works. White societies are mostly individualist, Middle-Eastern societies, and even African tribes are collectivists. East Asia's a mishmash of collectivism and individualism due to their history being thousands of years of getting stomped by people around them.
All cultures deserve to be preserved. Forcing cultures to mix doesn't create a new culture, it kills the existing cultures and creates an ugly amalgamation of people who hate eachother because their societies have functioned very differently for millennia, much like combining every colour on a pallet just creates the same ugly colour.