All I see at colleges and conferences worldwide are Macbooks. How is OS X Open Source? It actually seems to be worse, since it's legally tied to expensive hardware.
Also, Open Source products aren't really technically superior for a number of categories. I am sorry but Photoshop, Office, Exchange etc. are definitely technically superior. Software like Windows Server and SQL Server are competing with free products and still doing very well.
Imagine how much marketshare they would have if they were free of cost and MySQL/PostgresSQL and Linux cost the same as SQL Server and Windows Server now. How many would buy them instead of the free MS products? How many would pay the same as Office costs now for OpenOffice if Office was free? How is this technically superior?
Also, Azure runs Linux and other open source products quite well.