We're a Window$ free house; Linux is the daily driver on every single computer we have.
I have school age children. They have IT classes. I set up a machine with Mint, clean install, to serve has the school workhorse. Not one task assigned at school can not be done in the Linux box. My child came home a few worried a few times because the teacher disliked having a linux box in the room.
What happens is the teacher is terrified has they cannot load a single piece of software on that machine, as they do with all the other students, at will. The notion of explaining to all the other students they need to go to some site to download some program while my child just needs to fetch it (or already has it pre installed) from a secure repository is baffling. The knowledge that that humble and rather older machine can not be trivialy tampered with is mind disturbing.
At some point the teacher explained how to maintain the system (clean temp files and random junk Windows collects over time by just having programs installed and removed) and looked at my child and chidded that was something she could not do.
I taught my kid how to do basic system maintenance. Through the console. Like a boss. They upgraded the system while they colleagues were "busy" hunting down temp files.
I feel for the teacher, Windows is still the predominant OS that is used by businesses worldwide and it's unlikely to change any time soon. Ensuring the kids have some familiarity with it is important as when a lot of them go into the workplace their employer isn't going to give them a choice of OS to use. A number of schools in my country now provide kids with Windows laptops that can be managed through group policies. I can imagine the teacher feeling frustrated at times as their teaching material will be geared to Windows and may face challenges in being able to grade your kid.
It's great you have given your kid experience in using Linux and that should set them up really well to working in a Linux based environment. Hopefully one day other OS will be added to teacher's curriculum so that all kids have the opportunity to get hands on experience.
If anything more recently schools have been going the opposite direction. Moving away from Windows towards Chrome Books which is probably even worse from a being prepared for the future stand point.
Hey as someone who kinda grew up in that scenario, I really reccomend you show your kid what a windows dual boot is
Your kid doesn't exist in a vacuum. They have friends and inevitably your kid's going to be in a situation where their friends are like "hey, want to play this game with us?" And they can't because it's got a kernel anti-cheat that doesn't work with Linux. They're going to try and get into a hobby, only to find that the software everyone uses doesn't work on Linux and the alternatives that do are badly maintained and frustrating to work with. They're going to encounter a programme they need for school that just straight up does not work on Linux.
Sure you might be able to find a work around to all these things but like, can your kid? Because I speak from experience when I say that feeling like you have to be constantly running to your dad every time something doesn't work doesn't foster a sense of mastery, it makes you feel like you can't do anything on your computer because you're too small and dumb.
The teacher probably isn't "afraid" of the Linux box, they're probably frustrated that they don't know what's going on and can't help if something goes wrong. The programmes they'll probably teach your kid aren't a perfect 1-to-1 match to their Linux alternatives and they'll be left sitting in the back confused and upset while everyone else is learning about stuff in word and excel that you can't do in libre Office. You're not going to be known as the cool hacker dad, you're going to be put in the same category as the crunchy mum who doesn't let their kid eat sugar and needlessly restricts something that's just so petty to the layman.
It must have been traumatic for that Arch user to discover such rebellion in their child. /s
On a more serious note, if my kids find this post: I hope you know we can talk about closed source software if you're curious about it - and about maintaining a proper virtual infrastructure to protect the rest of the network from it.
