* Chocolate is an entheogen and an aphrodisiac. Yes, that actually makes it a terrific vehicle for magic
* It isn't addictive, but it is supremely seductive. Despite banning a bunch of other native stuff, not even the asshole conquistadores could resist the sweet siren song of chocolate.
* Ethics of magic rely a lot on cultural context. Where people routinely get screwed, the ethics tend to focus on survival rather than respect. If nobody gives a flying fuck about anyone else's free will, then the magicians in that culture tend to use magic to balance a very stacked deck. This is also why all the Afro-Caribbean stuff is so hardcore: only the most effective bits survived brutal oppression.
* Men would rather risk being hexed or poisoned than make their own morning brew.
* If you oppress people and force them to work for you, then you damn well deserve to be afraid.