I just don't understand why people think they can refute an argument that's been fleshed out into a book by writing a couple offhand sentences in response to a

I just don't understand why people think they can refute an argument that's been fleshed out into a book by writing a couple offhand sentences in response to a long form article on the book. Presumably the author would address popularly held assumptions to the contrary of his provocative argument in the book.