I get and send ~ 10 to 15 emails per week. Not even 1 of my regular 'correspondence' uses GnuPG. It's too complicated to setup and even harder to use for avg Joe, like bitcoin, he has to spent time understanding totally new concepts. And no one is willing to do that, unfortunately :-(
Unfortunately, all the glamour and the money and the code seems to track vanity crypto projects, and not so much of it goes to projects that make GPG more usable for normal people. Kudos to Google for taking a stab at correcting this.