Does that support modern gaming?
I think Microsoft just wanted to be in on the "Internet of Things" hype train. The Windows IoT Core is the cut back version of Windows designed explicitly for headless, IoT stuff.
The IoT means it is for people who can't afford having the OS vendor make the OS do things against their will. Which should be everyone, but sadly isn't.
Yes, the games themselves are proprietary, but that’s because they’re primarily art pieces, and proprietary licenses makes some logical sense in that case.