That's a poor usage of "just": discovering that "X is just Y" doesn't diminish X; it tells us that Y is a much more complex and amazing topic than we might have

That's a poor usage of "just": discovering that "X is just Y" doesn't diminish X; it tells us that Y is a much more complex and amazing topic than we might have previously thought. For example: "Life is just chemistry", "Earth is just a pile of atoms", "Behaviours are just Turing Machines", etc.