Goatse links would be the least of your problems. I’m imagining my Gmail account without the spam filter. Everything showing up in my inbox, not just the stuff in my spam folder, but also all the stuff they silently drop that I don’t even see. Email would be unusable.
Imagination often does not match reality. I have a (non-Gmail) account that is littered over the web, in git repositories and in multiple leaks. I don't silently drop any emails - the only server-side anti-spam measure I have a regexp to reject the usual spam subjects at submission time, which for normal senders will result in a notification to the user. The amount of spam is hardly at a level that would be anywhere close to making Email unusable.
