services shouldn't leak user email addresses or that those users use that service.

users shouldn't have to juggle different email addresses to maintain distinct identities on different services.

with gravitar, the user is opting into losing pseudonymity, seeing as it's pretty trivial to take lists of email addresses you want to hunt down, md5 them, and then check them against places that user gravitar comments to identify comments are made by someone specific )

with this suggestion, every user on every email server that supports it, which would likely include all the common large ones if the author had their way, would fall afoul of constant identity leakage across every service they use.

an adversary need only crawl different services and hash the user avatars, spam email servers with requests for addresses dropped in leaks or otherwise available publicly, and match them up to remove privacy from the internet