Interesting article (via Bruce Schneier) from someone who obviously knows a lot about PGP/GPG encryption, but doesn't see a future for it.
I can empathise with many of his points. I've had an encryption key for many years, but not used it much. There just aren't many people out there who encrypt or sign their emails, despite all the known issues. Doing it right is just too hard for most and the fact that many don't read their email on a PC these days makes it harder. When Phil Zimmerman created PGP back in the 90s most of us were still using dial-up and email was mostly plain text.
Using encryption properly involves verifying that you have the correct key for the recipient. Efforts like Biglumber and Keybase have tried to help with this. The latter is a very cool service as it uses encryption to verify your identity across various social services. You can find me on there. It's going to get more important to prove who you are.
I can only read encrypted email on my main PC as I don't have it on my phone or at work. The author of the article suggests using other services such as Signal to send encrypted messages. Open source solutions are preferred to avoid companies implanting back doors.
If you want to play with encrypted email or messaging then I'm happy to try it with you. In this age of surveillance we need to make encryption the norm so that it doesn't stand out.