The problem with local workforce is that you have less threats hanging over their heads. Ones you can threaten with deportation, separation from their children, or just shoot in the streets, are just more controllable.
Imported labour has less rights and will be more open to grovelling.
1. These people are detached from reality.
They would never see water that can be ignited because of the contamination so don't know the scale of their actions. Or
2. They think they have enough power to make the other countries worse, pressure on the EU, bombing the middle east, that making life worse for locals is offset.
Modern elites do not belong to any particular country; this is the entire selling point of globalism. They have no stake in any country's success.
We may pride ourselves on distinctions but when you put a white guy, an African and an Indian through the grinder, the same pink slurry comes out the other end. We're all just mince to them. We aren't even ruled from within our own borders anymore.