I did say, “almost impossible.”
But point taken. What’s the harm in having your son learn about Linux? Why are you so opposed to him learning about Linux?
Linux may not have helped your career, but why should your son necessarily follow in your footsteps? His IT career path may very well take him into the world of Linux. You never know. You can’t know.
For a 20-year IT veteran, you sound awfully ignorant about Linux. I find that most puzzling. Linux is not a toy OS. You don’t “play” with Linux.
Linux is a very solid industrial platform. It runs on everything from Raspberry Pi to IBM mainframes. It hosts a large portion of the world’s websites. It is a crucial piece of the open source movement. Linux is an enormously popular development platform.