In theory, you're right. But she talks about how it happens in practice. We can all sit around and talk about how this or that should work in theory, until one day we get a chance to do that one thing. And then most of us shut up because the real world is messy.
What if they have much worse paragraphs in the middle?
Do you think a book that has a particularly bad first few pages is more or less likely to have a lot of poor content in the middle vs. a book that has a really good first few pages?