If ProtonMail was solely for users who want to maximize privacy, it'd be as difficult to use a ProtonMail address as your primary email as it is to do your norm

If ProtonMail was solely for users who want to maximize privacy, it'd be as difficult to use a ProtonMail address as your primary email as it is to do your normal web browsing through Tor. Services that are primarily used to hide shady stuff from the FBI tend to get shut down or, failing that, heavily stigmatized.