As an immigrant myself, I've heard this take a lot. I despise it because it treats us as a resource that you can allocate here or there as needed to solve problems, ignoring the person themselves and their needs and wants. What if the "high performant brain" does not want to sacrifice their own well-being for the sake of "improving their country"?

If "anti-imperialist" Westerners truly care so much about brain drain negatively affecting other countries, they should go live in those countries themselves and provide their services there for the sake of greater good. But very few actually do so, and even fewer are willing to do it on any kind of non-temporary basis.