>Division and separateness is not a good thing and it holds back true progress,
This is true.
However we need to keep in mind that we're talking about true-humans here, not human looking creatures who share the same common ancestor.
There's a good reason why all aliens seem mono-ethnic, usually either Asian looking or Nordic. Their societies either genocided the non performing lesser beings or they didn't have them to begin with.
Earth needs to do the same with our legacy baggage species. They function like a god damn anchor on any true progress.