Picture this, if you will:
You are a busy person. You get too many emails. Loads of those emails are irrelevant, but you get them every month, like really shit clockwork. You’re clever, so you take the time to unsubscribe. It takes a few clicks, but it’s a good investment of your time. You’re all done and you feel happy: one less piece of junk mail and few less RSI-inducing clicks.
Then, THE BASTARDS SEND YOU ANOTHER EMAIL.
Disappointed that you’ve abandoned them, the automated marketing machine sends you a good-bye message. So the marketing spammers recognise your desire for less email, and send you one last email.
Why can’t they just let it go? And why do some unsubscribe options demand a password that you didn’t even know you had?
If people want to leave your unstoppable spam machine, just let them. And never darken their inbox again.