It’s not fear. It is, if you’ll pardon the appropriation, mild annoyance.
Some people enjoy learning about computer programming, either professionally or recreationally. That’s great for them. But people need to understand that not everyone shares their enthusiasm.
I have spent just enough time in computer programs to know that it is a subject that holds no enjoyment for me. So I will not enjoy it if I am forced by circumstances to spend time learning how Linux works. I will begrudge every hour I have to spend doing that instead of doing something I would have enjoyed.