That may be one theory. But it looks like centuries separated out the oral composition of the Vedas and the birth of Buddha, so if there was a monotheistic god at one point in Indian tradition it wasn't Buddha who took that god away.
People are going to believe all kinds of things for the forseeable future. If you think you've got the right philosophy, try to live by it and we'll see. But I doubt everything you disapprove of is just going to roll up and disappear.
Nimrod (Amraphel), Buddha, Kant, Hegel, Marx, Freud, Nietzsche et al share the distinction of being ‘God killers’ and inventers of philosophy’s and systems whose greatest appeal is to individuals who hope to perfect and/or purify themselves even though there is no source for self.
True Christianity is neither a religion nor a philosophy but rather a personal relationship with the living Spirit of God.
You said “But I doubt everything you disapprove of is just going to roll up and disappear.”
Reducing the profound meaning of the essay to ‘spite” (disapproval) is childish. And no, none of it will roll up and go away because there is a reason for its’ existence. It exists for those who prefer empty philosophy’s over a relationship with the Spirit of God. It exists to serve as a winnow, so to speak.