So how does one migrate from the two password to the one?
I like the idea of protonmail, but since they made it incompatible with normal public key encrypted mail it's pretty useless for many of us, unfortunately...
If we're to push end-to-end encryption to the masses, then we ought to try to get forward secrecy in it, and it should be quite invisible to the user.
That's not to say that ProtonMail is getting it right, but it's at least one of the few that are striving to move in that direction.
Relevant post from Moxie from Open Whisper Systems:
Moxie writes from a personal perspective and you'll notice he never claims to have something better in hand. His Signal still lacks utterly basic functionality provided by PGP, most important among them the ability to transmit arbitrary attachments (Signal only supports an undisclosed list of media attachments) but also including the ability to retain your messages long term in a particular location. Meanwhile, many of the tradeoffs made to make Signal easy could be made using PGP: Automatic generation of keys; centralized key repo; centralized mapping of keys to contact points (email/phone); trust by default.
If you have a replacement for GPG and E-Mail please tell me what it is.
But adoption is even worse than pgp
Today's messaging services (Signal, Wire, Telegram, etc...) outpace email by a significant margin.