IIRC Zed Shaw had an essay on this.

1. He uses lay (i.e. non-technical) definitions of "indirect" and "abstract" to argue that the technical definitions are somehow flawed. Words have different meanings in different contexts, but he rejects those different contexts.

2. He argues that abstract classes in Java are actually a form of indirection because the abstract modifier "creates an indirect path to the real implementation". This is after he covers that "abstract" can mean "a concept or idea not associated with any specific instance".

3. He claims that no lay definition of abstraction permits the idea of "swapping out the implementation". He fails to understand that, from the client code's point of view, "swapping out the implementation" is a direct consequence of coding to the abstraction.

4. In the words of Rich Hickey, I think Zed is conflating Simple and Easy.

I don't doubt that Zed saw something legitimately objectionable and that drove him to write the essay. But in trying to formulate his point, I think he ended up conflating ideas, relying on false premises, and built an argument that didn't have much of a logical progression.

He's essentially saying "I'm right and everybody else is wrong because I looked it up in a dictionary."