Just think of all the Steam games that are only available on Windows!
I am sure you mean "designed for Win32 API."
They mean that those apps are currently deeply integrated with NT and switching is very expensive for the developers. See most games as an example.
Some were, plenty were not, and C is nothing special as a turning point in that.
> If you have to call on specific features of a particular OS when writing business application code, that's a problem with the OS.
No, insofar as it's a problem, it's a problem with the application language or libraries, in that they don't abstract sufficiently the deployment platform.
Now, if they are bundled with the OS, it may be the same product as the OS, but it's not really an OS. problem.
Which ones were not?
Ah, ok. I meant general purpose languages, not languages specialized to particular applications. I should have made that clear.