Most people are actually passively opting for Windows.
Computers just come with it, or if somebody install it for them, Windows is the default expectation.
MacOS comes with very expensive Apple computers, and most people just choose Windows. The idea of Linux either never crosses their mind, they may not be aware of its existence, or think it's some geeky server thing.
Most people opting for Windows, thereby, don't make a rational decision between Windows, Linux, MacOS, FreeBSD or whatever. For them, Windows is just how computer works.
I couldn't look the same at Windows after about two weeks on Linux. Seriously, Windows is THIS bad.