Are you sure that argument still holds when everyone has Android/iOS phone with apps that talk to Linux servers, and some use Windows desktops and servers as well?
There isn't, and never was, a benevolent dictator choosing the OS for computers in medical settings.
Instead, it's a bunch of independent-ish, for-profit software & hardware companies. Each one trying to make it cheap & easy to develop their own product, and to maximize sales. Given the dominance of MS-DOS and Windows on cheap-ish & ubiquitous PC's, starting in the early-ish 1980's, the current situation was pretty much inevitable.
To add detail for those that don't understand, the big healthcare players barely have unix teams, and the small mom and pop groups literally have desktops sitting under the receptionist desk running the shittiest software imaginable.
The big health products are built on windows because they are built by outsourced software shops and target the majority of builds which are basically the equivalent of bob's hardware store still running windows 95 on their point of sale box.
The major players that took over this space for the big players had to migrate from this, so they still targeted "wintel" platforms because the vast majority of healthcare servers are windows.
Its basically the tech equivalent of everything evolved from the width of oxen for railway.
Because of critical mass. A significant amount of non-technically inclined people use Windows. Some use Mac. And they're intimidated by anything different.
There's a bunch of non-web proprietary software medical offices use to access patient files, result histories, prescription dispensation etc. At least here in Ontario my doctor uses an actual windows application to accomplish all that.
Then they use those apps. The point is that since they usage of the OS as such is so minimal as to be irrelevant as long as it has a launcher and an X in the top corner.
