I suspect this is less about when Windows declined and more about individual computing journeys. Early exposure (home, school, work) tends to set a baseline that’s hard to shake.
Microsoft had realyl good engineers and talent. Microsoft internally has gone to shit. They hire an army of H1B's and all the talent has left. Shell of a company on the Windows side that anyone working with them can see. It started a couple years ago, but it's really gone off the deepend and will just get worse. I say this as a windows expert and someone who thinks linux is crap.