[Ant11]

Linux brought a large new demographic (hobbyists, students) to Unix at a time that it was expensive, little used and dying. The Linux movement, as opposed to the Linux software, was a true revolution and not easily replaced. Effective movements are a lot harder to build than effective software.

Another counterexample would be the internet itself. It could very easily have gone wrong and we would have been stuck with the likes of Compuserve and AOL.