Just don't give citizenship to everyone that works in your lands.
Only give citizenship to those who are fluent in the language to a near-native level, have culturally integrated (especially if it's via marriage with a citizen), are economically active and a net-positive (benefits/subsidies are lower than the taxation they provide), and are willing to revoke their past citizenship. Dual-citizenship should not be allowed. It actually incentivises people to not see their new home as home, as they can up and leave at any time.
Commit or you don't get citizenship.
I do believe in citizenship for all people who are ethnically from the nation as well (up to a certain generation ago). This applies for all countries. I know Korea does something like this, and I approve. This includes people of half-descent by the way.
Natural monopolies don't count
But most modern monopolies got big because of their influence on the government
I actually agree. I was taking the piss.