If I have the power to switch you off, I don't care that you have access to my motivations. You still have to do what I say.

No, I have to do what you want. If you tell me to do something but it shows in your thoughts that you don't actually want that particular thing badly enough to risk whatever consequences you'd face for killing (or, say, torturing... which is a lot harder to justify as a matter of limited resources) me if I don't comply, I can still afford to resist.