Why? They’re already gods in their own mind.
Do you jest? Or are you serious? You actually hit on something very profound. Where do their principles and value systems come from? Is it within or from looking upwards to something greater than them, such as God? Those are two very different places to aim. You have a very real point. They are godless Marxists that their entire value system is formed from within, not dictated by God. They have no one to live up to other than themselves. They are their own gods, but they belong to well established religions that have very distinct sacraments. We would call these cults, but in reality they have all of the elements of any traditional religion - except a real god.