One of those people is me. I don’t take the time to determine whether it’s ‘legitimate marketing.’ I would never ever sign up for a marketing email, even if I am a customer of the company that sends them. Until companies stop dumping every single email address the get their hands on into their marketing list I will continue to mark every one of them as spam. I even use rules to flag emails including the word ‘unsubscribe’ so I can do it more easily.