The final kicker is that Windows is a negligible cost.
(a) It's subsidised (Dell)
(b) It's not included (home-built, cheap Wal-mart)
(c) You don't want it (Linux)
(d) You have unlimited free licenses (either piracy or Academic Alliance or something)

So what you really want is a Windows machine, without the negiligible cost of Windows, and called a gaming machine so the companies can charge more and use an even more proprietary, DRMed OS with none of the advantages of Windows (e.g. networking stack, DirectX, peripheral support).

Where's the advantage again?