My dad is in his mid 60s and has been happily using Ubuntu for the better part of a year. He now no longer has to worry about most malware or windows updates interrupting his workflow. I think you are really overestimating the complexity of using Linux as a normal user.

This. Choose the right distro (ubuntu or derivatives, or elementaryOS) and it's as easy as windows for everyday tasks.

And for not-everyday tasks, you can just ssh in and fix it for them.