People talk about market share and how good it is, but they forget the downsides.
Imagine you are huge company doing something, and you have an installed base and developed technology. He didn't have to deal with an installed user base. The real innovation either never happens, takes decades, or only happens when the big bloated company buys someone else who has done the work for them. NT was part Dave Cutler recreating VMS for Microsoft, flavored with borrowed Windows, DOS and Xenix code. This is all over the industry.