I was going to suggest maybe some greasemonkey/custom CSS to hide the popup, but then I saw they're using these random ass CSS class names and just couldn't be bothered with it :/ Yeah, at least an option to not get bugged for x weeks/months would be good.

I don't even mind using my email, like, it's not secret -- but I also like not having to, and I respect when sites allow for it, on a craftsmanship level; it divides tools from toys. I have a PW manager, the passwords are long and super random, adding the email address adds nothing (For me).