Some enterprises are, perhaps most. But tablets and phones HAVE made a dent, and some places are BYOD even at the computer level.

e.g. Google is very far from 99% Windows - and though it is not your standard "enterprise", it is far from unique.

Sure, but why make the commitment to build your whole thing windows-only when you are only a tiny bit away from actually doing it platform independent. Like, for having options in the future, and stuff.

It would be adding several more months to project completion, and then recurring maintenance costs that overtime costs much more money.