And GNU utilities were obviously used a lot on Unices and when Linux didn't yet exist. Also bash is more or less similar to Korn shell, which was used earlier than you may think. And also zsh, despite people perceiving it as very modern, is older than you may think.
Anyway, if a program written for Unix works on a Unix clone, it doesn't cease being a Unix program. POSIX was a standard for Unix.
I don't get what are you arguing for. Especially since I meant bourne shell scripts, not bash scripts.
You very much can avoid using a Unix shell. Your average Windows user has never used one, and neither do most macOS people even though it’s included with macOS. Likewise most people will never have to setup a web server.
I've said once that I want to give a taste of something. I was more general with things one can't avoid, as in "one can't avoid computers and the Internet". And this was pretty clear from the context, either you are playing dumb or you want to defeat someone in an argument, in the latter case I don't care because I see you are not doing that.
A taste of real things I'd want to give to help them connect their inner abstract idea of how the world works with actual material things. They will have that idea, I absolutely trust every person to develop that on their own without help. Without that they might not believe themselves when they should.
None of this is going to stop someone getting scammed. You can have plenty of technical knowledge and still get scammed. I got scammed trying to sell a laptop for example. Teaching them how paypal works and to avoid using the friends and family option is much better for this purpose.
See previous.
If you want to give people practical skills start with adblockers and how to reinstall Windows, macOS, and Linux Mint if it goes wrong.
I don't want them to hate computing. This will lead to that exactly. Especially PowerShell.