More like Superclasses used incorrectly make your code brittle so don't use superclasses. In so far as I have never found a use case for a class hierarchy 5

More like Superclasses used incorrectly make your code brittle so don't use superclasses. In so far as I have never found a use case for a class hierarchy 5 deep I agree with him. On the other hand the argument that because you can do it wrong means you shouldn't do it all isn't compelling. I don't think there is a language or language feature that you can't use incorrectly.