Ah, I see. I agree, more context would be better for the beginner to understand why the lessons are the way they are.
I tried to explain the benefits of vim in the "Why Vim?" section, but I should really go into why using and learning vim will be slower at first than using the editor you're already comfortable with, and how it might be worth it in the end.
IMO, the choice of nix editor is always somewhat contextual depending on how much full stack work is being done. If one is doing a lot of systems work (ie a lot of bash commands), then one inevitably wants to set a default editor on the systems being used. While I choose vi, it really depends on the number and type of systems being regularly accessed, and your personal preferences. For me the use of a terminal editor is just part of the seamless flow of using the command line for everything else. I personally don't think it is especially valuable to consider terminal editors in isolation away from bash, other than to become familiar with key strokes.
I tried to explain the benefits of vim in the "Why Vim?" section, but I should really go into why using and learning vim will be slower at first than using the editor you're already comfortable with, and how it might be worth it in the end.
Thanks for the feedback!