Re: Ch. 8 - The Grand Design
Asking "why" about everything is invalid. In some cases, it's appropriate instead to ask "how". My kid is currently 3 years old, and asks "why" about everything(and I love it).
Nested within the question is the assumption that the answer will be teleological. It is an appropriate question to ask when wondering about a person's intention. It's an inappropriate question to ask when wondering about many large questions in science. You have to justify the teleological assumption first, and show us there is "intention" towards which the question of "why" can be asked.
Science is answering the questions it's able to bite onto. Most of the "why" questions are misuse of language, rather than a failure of science.