I think it's fair to say it wasn't engineered code.
Great insights that got the codebase started but it wasn't written by a professional software engineer. It doesn't take anything away from the accomplishment though.
I denounce your claim as far as it is about textbooks and established science and not corporate invented fake engineering practices that involve a lot of generalization and abstraction layers and pointless application of void OOP ideas that have ended to software bloat and disasters like Windows.