I disagree. For vast, vast majority of cases, linux would likely do the trick these days. People would complain initially and, predictably, would complain again if new functionality was taken away from them. But that is just human nature.

Lets talk reality. More and more applications users access live in a browser.. you technically could run the entire company on dumb terminals if you were so inclined ( and jobs were sufficiently.. in dire of automation, but for one reason or another human is doing those ). Windows is not needed for that.

You could argue banking/finance with excel ( and there are some neat things Office introduced with 365 ), which is presumably why that sector is going to be locked in for a while, but then.. my last class at university, all kids were running google docs and they will be making decisions one day. I am not sure that bodes well for MS/Office/Windows.

As for "accounting, customer management, CAD, printing, publishing, manufacturing, simulation, advanced reporting, large document processing, centrally controlled IT", you might be right, but somehow I doubt it. There is nothing magical about Windows. It is currently held by inertia and contracts, but even inertia ends eventually.