I'd have a hard problem going to every single website where I ever made an account and changing the email preferences.. Assuming I'm a normal human being, there are bound to be sites that I forget about and someone dedicated enough could then get access to my accounts on those sites.

Not a security risk I'm willing to take, when I could simply leave that email address dormant. There's not really a huge shortage of good email addresses if you're willing to pay $10 a year for your own domain.