I get pissed off whenever I unsub from an email and get a message saying it may take two weeks for them to honor my request. Like what the hell is going on that

I get pissed off whenever I unsub from an email and get a message saying it may take two weeks for them to honor my request. Like what the hell is going on that it takes two weeks to flip a flag, even across multiple databases? Because they sure as hell won't delete your email address.