Since your example isn’t accurate, I’ll modify it to make a more apt analogy.

Cust: I am looking for a passage of text from an obscure book. Clerk: Ok, what is the text you are looking for. Cust: It’s called “Ancient Unholy Incantations” Clerk: oh, why do you want that book? Why why why? Cust: I can’t say. Clerk: Tell me! Or else I can’t help. I physically can’t. It’s not that I don’t want to because I don’t believe your intentions are good and need convincing. Something would prevent me from doing so (can’t say what). Cust: Ok well it’s sort of for a lot of different purposes, like just random stuff, maybe for making my dog happy, or for helping grow my garden. Clerk: No, no, tell me more! What is it? You haven’t given me enough information. I can’t help you! Cust: Are you sure it’s not just that you don’t want to because you assume my intentions are bad? Clerk: You are alt-right!!!