It's like cars. A lot of people drive them every day. Not as many people know how they work or how to fix them.
If someone spends their entire life studying medicine or law or art, etc., or any other trade that has nothing to do with their computer OS, I don't blame them for simply not having any remaining brain space to support an entire new set of skills just to maintain their computer when they are used to Windows or MacOS doing everything for them.