A key point you ignore in my comment is the "caught at compile time" part. If generics breaks backward compatibility, but the breaks can be caught at compile ti

A key point you ignore in my comment is the "caught at compile time" part. If generics breaks backward compatibility, but the breaks can be caught at compile time, upgrading a medium codebase may take only an afternoon, and that would be reasonable commitment. Huge difference from the Python 3 scenario.