People don't buy Macs because they work well with an iPhone as far as I can tell. They buy Macs for all sorts of other reasons, but that doesn't seem to be one of them.
Every corporate office in the world is running Windows. I'm pretty sure people are going to continue buying whatever they use at work, so unfortunately for HN, Windows is here to stay...(sorry!)
While many companies do use Windows, many others do not, including some very large ones. You think they are using Windows at Apple? That's the world's most valuable company and they have 70000 employees. What about Google? It's another huge company with tens of thousands of employees and you have to beg for permission to run Windows there, and very few do so.
I think Windows has a lock on mid-sized businesses that are large enough to have serious information management challenges, but aren't big enough to solve them. Outside of that zone it is by no means universal.
I'd say that outside of your two examples, you'd be hard-pressed to find a Fortune 500 company that doesn't have >90% of its corporate fleet (not servers) being Windows boxes.
See: http://ben-evans.com/benedictevans/2015/7/8/capitulation http://ben-evans.com/benedictevans/2015/11/7/mobile-ecosyste...
Any additional computer purchase is some kind of conscious choice, and people will default to what they are familiar with. I.e. iOS and Android. This is a big hurdle for microsoft to overcome to convince anyone to buy a computer from them. That's my point, and I think it will be very difficult for them to accomplish at scale.