I've tried to get multiple non-family members set up with Linux and have failed, with constant bugs from Linux, and confusion from the family members. Windows is far more reliable and easier for them to use.

This clearly invalidates your point, and supports "Linux would be either painful or more realistically a no go", because it's obviously not enough for some relatives to be able to easily use Linux - most of them need to be able to. The fact that you have more capable-than-normal relatives or more Linux-friendly-than-normal hardware is irrelevant to the fact that most people do not.