I doubt they will care what some of their customers say about interoperability with Unix. The clear answer from their point of view is get rid of Unix. The desktops and the servers that will always work best together will come from the same vendor -- them.
I think a lot is marketing too. I didn't even know that there were linux games other than the simple console types and doubt that I'm unique.
The difference between illegal gambling and state lotteries is easy -- one's legal and the other isn't. The state says so.
I doubt they will care what some of their customers say about interoperability with Unix. The clear answer from their point of view is get rid of Unix. The desktops and the servers that will always work best together will come from the same vendor -- them.