Where it's sketchy to find Windows is inside the chassis of some piece of specialized equipment with its own control panel. You may not even realize that what you're working with is a full-screen Win32 app until you get a bluescreen or taskbar popop or something. Then you learn that in addition to the domain-specific software/hardware and what you're trying to use it for, you've got a whole Windows desktop worth of reliability risk in there.
If it's just a touchscreen or hardware buttons, you may need a key to open a panel where the keyboard/mouse are, or to bring your own keyboard/mouse, in order to navigate the Windows part of the interface to fix the problem.
Obviously if it's intended to be networked to existing desktops for control over a LAN, the client software will be Windows, but even then you hope the server isn't.