Let's assume it really is only about code monkeys. Those asian code monkeys won't demand silly things like... unionization or decent living conditions. They are less likely to have problems with creating autonomous weapon systems that integrate facial recognition.

But it's not about those people. It's about experts in IT infrastructure, AI, researchers, etc. Those kind of people don't fall from trees and know that their expertise is well sought after. And if the US is not a safe or attractive choice, they go elsewhere. Simple as that.