Anyway, if you want to get into it... Microsoft dominated the consumer market in the 1990s. The same people you say who were not nerds and didn't care ... Didn't care to get an Apple machine either, they got whatever everybody else got, which were Wintel PCs. Most didn't care if something else had a nicer design or UI or was friendlier or more efficient. It was Win9x almost everywhere.
I think this negates your "Microsoft went after businesses" hypothesis somewhat. They had total domination everywhere, and maybe got a little lazy or complacent and the lead eroded, at the same time Apple got Jobs back and grew as a consumer brand due to iPod etc. But Microsoft is still a major force outside of techie circles.