As someone who gets a relative ton of unsolicited Kickstarter spam, I appreciated that Mailchimp was the only marketing email provider that seemed to actually use "this message was unsolicited/I never signed up for this" signals and it was an Unsubscribe button I felt able to trust. (As opposed to some other worse providers where Unsubscribe sometimes just means "Oh look, an actual human clicked the button, time to send more spam.")

I'm not sure Intuit will intentionally break this trust, but it will be something I'm probably going to be wary of happening unintentionally.