I wonder if Microsoft does this because gaming has been one of the biggest differentiators for their OS. That's an advantage that is rapidly fading and they want to hold onto it as long as possible.
Not sure if that stance is going to be relevant much longer. I recall Apple releasing a new framework that actually had some substance during their last keynote. I think Linus did a segment, they were running cyberpunk on Mac at 30FPS, not ideal sure, but it's a big step up.