The way I see Mailpile becoming popular and putting a dent in dragnet surveillance is not by everyone downloading it and running themselves but a trusted third party running it and holding keys for a relatively small group of people.
Some will complain that this way the third party can still access the key and mail encrypted for it. That's true but also a massive step up from everyone on the wire being able to read your messages.
Now, an intelligence agency can just siphon anything and everything. With a large number of independent e-mail providers, only narrow and targeted surveillance would be feasible.
All that without giving up any convenience of webmail.
Some will complain that this way the third party can still access the key and mail encrypted for it. That's true but also a massive step up from everyone on the wire being able to read your messages.
Now, an intelligence agency can just siphon anything and everything. With a large number of independent e-mail providers, only narrow and targeted surveillance would be feasible.
All that without giving up any convenience of webmail.