Linux exists solely because he made it a collaborative endeavour from the start.
That is the important part. If Linux had tried to compete with Microsoft as a closed-source operating system, no one would have used it – who would use a tiny, buggy (back then), incomplete, closed-source operating system made by a few guys in their spare time against a very popular, feature-complete, close-source operating system with billions of dollars funding its engineering effort?
What makes Linux popular is that it is collectively owned, that is as much a feature of the operating system as any technology or algorithm written into the source code itself. That feature is what set it apart from Windows or Mac OS.