>the cost of switching is just not that high

Oh, my sweet summer child. Please realise that such blanket statements like that are profoundly ignorant. (Note: I'm running an entirely Windows-free household. )

The problem is changing the way companies build themselves up to work. Business logic. Even for medium-sized companies (100-1000 heads), what you're proposing is paying scores of business analysts months (years?) worth of time to review business processes, before you even get the teams of IT people to start making the switchover.

And that's not even taking into considering the fact that many large software packages simply do not work under nix and there is no realistic alternative. Basically every industry related to engineering simply cannot switch.

The processes and systems required to build Big Things in the real world are gargantuan and terrifying and sickening. Companies spend hundreds of millions every year putting up with Microsoft's bullshit because there is no alternative.