This article is a little long, but stay with it: because Mark Rushdoony nails it.
“Babylon is the kingdom of man,” opposed to the Kingdom of God. It is human beings trying to be gods.
If your Bible reading has brought you around to Revelation, this essay will be illuminating. It’s a “big picture” view of Revelation–speaking for myself, at least, something which I’m always in danger of losing in the details.