When grandpa buys his computer he doesn’t want to have to install an OS.
Correct. I think that is the biggest hurdle to desktop Linux. People in general don't want a computer--they want an appliance. That's fine. I have no issue with that.
If Linux came preinstalled on more than a few (there are some Linux-only computer makers out there, as well as a few Dell computers that come preinstalled with Linux) computer, there would be a much larger market.
When grandpa buys his computer he doesnt want to have to install an OS.
I bet Grandpa is so far behind in his updates and infested with malware etc
You usually have to install the OS when you buy a computer. It is just done automatically.