His answer was accurate. The spread of the Good News of Christ risen has a positive effect on individuals, families, societies, nations and the world in general.
Theonomy simply says we must begin with the family to create strong and upright members of society in order to improve that society.
I don't think that's such a bad thing.
Theonomy presupposes there is a right and Scriptural method of living which is more "correct" than all others. Now we can debate what that "more correct" position is, but as a society it is good that we at least acknowledge that some "optimum method of living" does, in fact, exist.
It's the humanists and socialists who want us to think there are no absolutes. Certainly no absolutes given by God.
So do you think it's okay for a family to kill a disobedient child? That would be theonomy starting at home.