Seriously, for Chinese being Chinese means more than being American citizen. And that is so for many other ethnic groups. Russian will stay Russian, Japanese will stay Japanese. American passport is nice to have.
For most people their family means more than their country. And for some ethnic groups Fatherland (or Motherland, since we mentioned Russians) could mean more than you think, even generations after relocation. Don't hire Russian to attack Russia. Don't hire Chinese to investigate Chinese state hackers. It's plain stupid.