Myself, instead of unsubscribing, I filter all emails. I stop receiving them, and they still have to pay for the email they send to me. It works every single time and I don't have to play any games like the ones in this article.
That's actually the punchline of the article, which you missed. It's bad UX to put the button at the bottom and causes people to go through the checkboxes unnecessarily.
It's bad UX though; the button could have been at the top.