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.
The author probably exaggerates, but identifies a very valid point. You really don't want to have this kind of confusion about something that you are planning to trust your secrets to.
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.