And this particular sysadmin-for-my-family will no longer allow windows to be installed on any of our computers whenever they are in need of a reinstall.

Windows is becoming more and more like Facebook. Too many users changed a setting you don't agree with? Just block access to that setting or call it something else to confuse enough people to the point that the numbers are "good enough" for management.

Almost every time I visit my parents, my mother's Windows 10 laptop has reverted at least one of the changes I have made.

I used to keep a copy of Windows available via dualboot on all of my laptops, just in case I needed to print something in a remote location where whichever flavor of linux I was using didn't support. Not anymore. Linux Mint serves that requirement just fine.