I only have two data points: I've contracted for two Fortune 10 companies. Both companies had Windows on the Desktop. But their Big Data / Big Iron was linux and solaris. Indeed the license managers (FlexLM) that authorized software for those desktops? Solaris.
Needless to say both of these companies were outside silicon valley.
So do you have data on that? Just doing some googling it seems that Walmart started out as an IBM shop, more recently Oracle and HP are mentioned. Are walmart buying Microsoft licenses to run Oracle on the HP boxes? I mean, they could be, but I think it would be unreasonable to assume that is the case.
2) I am rather interested to hear what you mean by "deeply entrenched in the real world". Are Google's and Amazon's profits somehow not real?
The way my GP alleged that no big companies use Windows as a platform came off as snarky and represents what I think is a skewed, SV/web-startup centric point of view.