I have "taught" encrypted email for many years to different types of people.
I'm surprised to see that most non-technical people that I assisted had a better understanding of these same tools than the author.
Generating the key using Enigmail has always worked for both Windows and Debian/Ubuntu (those are the top OSs people brought), finding a person's key was a pain a few years ago, I love the new UI.
My conclusion: The author probably had his mind set before even starting.
EDIT : Enigmail now allows you to enable encryption/signing by default, this prevents users from sending accidental clear-text emails.
I'm surprised to see that most non-technical people that I assisted had a better understanding of these same tools than the author.
Generating the key using Enigmail has always worked for both Windows and Debian/Ubuntu (those are the top OSs people brought), finding a person's key was a pain a few years ago, I love the new UI.
My conclusion: The author probably had his mind set before even starting.
EDIT : Enigmail now allows you to enable encryption/signing by default, this prevents users from sending accidental clear-text emails.