What are you talking about? Windows isn't a closed eco-system, beyond the 50,000 employed directly by Microsoft there are hundreds of thousands if not MILLIONS of jobs created to implement, maintain, enhance, extend and embrace Microsoft products. MS doesn't lock you in to anything and in the case of schools and businesses those businesses are choosing to lock-in to a specific vendor for business reasons - not ideological ones.
Believe it or not, the world wants accountability and you don't get that with open source since the accountability falls squarely on your own resources in most cases. People want a large resource pool, people want a stable business, support they can rely on and an infrastructure than can grow with their business.
There is plenty of open source software regardless of the platform to support academia, small businesses and those that simply hate Microsoft. There is also plenty of Commercial software as well.