Partly, the issue isn't "they would have to learn about Linux, and that's bad", it's "they would have to learn about Linux, and they wouldn't want do that, and so they would get frustrated and quite likely give up on it, and my recommendation would have been a waste of their time".

The other part is that they're not necessarily wrong not to want to learn about Linux! Learning is great, when it's something interesting or valuable. But if I'm not interested in the thing, and my time and mental resources are limited, and I have a good enough alternative, I think it's absolutely fine to avoid it.

Most of us choose to drive a car that just works, and take it to a mechanic when it doesn't, rather than buying one that requires and rewards tinkering. Maybe you're into cars, I don't know, but I bet you take this attitude to at least some of the useful objects in your life.

Because although sometimes annoying, people already have a good alternative making the hours required to invest in something they're not interested in a very high price.

It's the same reason why as a software developer I use Visual Studio Code and don't plan to learn (neo)vim.

I (like many who'd have to learn Linux) have better things to do.

It should be a choice, not a requirement. With Windows you can get your work done without knowing much about Windows itself, but with Linux you're forced to understand every level of the entire OS so you can debug it first and then maybe get your work done. For an OS built around user freedom Linux sure doesn't give its users much choice on how to use it.