When you select the Fat Burn program on the Stairmaster it has you enter your weight, desired difficulty level, and workout time via a keypad, then prints on its screen, “Enjoy Your Workout” which always prompts me to think, “Don’t tell me what to do!”
In English we don’t have much in the way of overt marking of hortative/optative mood. Phrases in which you express a desire for a person to have a certain experience are grammatically indistinguishable from ones in which you command them to have that same experience. I’m usually fine with this. When a person tells me to “Enjoy your weekend” I appreciate their good will. I don’t take it as an attempt to micromanage my free time. Coming from a machine, though, the same construction bugs me. So hortative-imperative distinctions serve the same vital social function as so much of grammar–they make it clear who we think should be in charge.