Why don't you give me that book? Why don't you go to the store and get some more milk? Why don't you make me a sandwich? In these examples, the speaker is clearly not asking for the reason the listener is not doing the action in question.
Why don't you give me that book? Why don't you go to the store and get some more milk? Why don't you make me a sandwich? In these examples, the speaker is clearly not asking for the reason the listener is not doing the action in question.