Linux

That's fair, but at the same time as you mentioned most people use Windows because their computer comes with it. Now, while generally just browsing the internet and doing office work is simple even on Linux - what happens when they do run into a problem (say my coworker, who ran into graphical glitches with Fedora when not using safe graphics mode)? How likely are they going to have someone around them who uses Linux to help them troubleshoot the issue? When they try to work on a document that they've gotten from work, or school, then submit it only to find out that Libreoffice mangled the formatting causing it to render completely incorrect to everyone else whose using Windows at their workplace/school. How many of those folks are going to have an IT team at said place whose able to help them correct the issue?

You and I would be around to help with that (if its possible - using Libreoffice again as an example, there are some cases where MS Office just does not agree with the way LO saves documents), but given that Linux users are many order of magnitudes less than Windows users - this is just not likely to be the case for the average population.

I get that this is definitely a "Chicken & Egg" problem of course, but the reality is that this is the current situation, and short of Microsoft royally pissing off not only users but PC manufactures, this isn't likely to change...