I suppose that's one way to read Steyn's piece. A strangely Statist idea of Steyn's intent, but I suppose if that's the way you read it...
Personally, I read Steyn as saying that Western Civilization -- the font of individual liberty and the rule of law -- is killing itself off, and he thinks that's a bad thing. It would be "enough", demographically speaking, if we as a culture simply refused to Murder the infants whom we are already conceiving -- not that more conceptions in the aggregate "must" be encouraged.
What a simpleton you are to actually read an article to get the main point.