I doubt more than 1% of marketing emails are desired. They may as well be spam. Forgetting to check a box, or to uncheck a box, or accidentally checking a box, doesn't make them wanted. Not wanting them anymore but also not bothering to go disable them doesn't make them wanted. It's fair to class them with spam.

[EDIT] I mean 1% of marketing emails where there's any relationship between the sender and the recipient whatsoever, of course. All others are spam, clearly.