Anybody who thinks contacting remote peoples and integrating them into our society is of course an unalloyed good why wouldn’t they just love it, needs to consider the science fiction scenario where aliens land, announce we’re part of the Galactic Community now, thousands of moralizing alien anthropologists will be along next week to tell us how much everything about our culture sucks and has to be changed, our diet is going to be replaced with Galacta-Brand Protein Paste (which is edible for humans, but just barely),and you’re all out of work because Earth industry can’t compete with superior and cheaper galactic imports that will be flooding the planet soon. Oh and the mineral rights to Earth happpen to belong to the Zlorpians three stars over. The mountain-smashers will be landing on Tuesday. The good news is, we can now cure the common cold! You can’t afford it, though, so don’t ask.
Because even sans the forcible conquest, genocides, and displacements of the past–which are not nearly far in the past as people like to think, and in some places aren’t even in the past at all–catapulting an entire culture and people into a complete different context which drowns them out and overwhelms them is not a recipe for harmony and prosperity. And that’s even before the bright-eyed bureaucrats show up wielding clipboards and announce that your land belong to Brazil or Papua New Guinea or wherever, and you are under the authority of people thousands of miles away who you never heard of until this very moment.
(Or just go watch the new Rick and Morty episode, which summarizes this all succinctly in about three minutes of screen time.)