Windows is touted as the largest git repository. What service like Github or Gitlab could handle something that massive? I'm sure they could scale eventually but if that ever happened MS would likely have to house the repository and at that point they might as well keep it closed source or open source with a subscription cost that goes into the infrastructure upkeep.

I'd honestly love for more portions of Windows to become open source and slowly work up to the full repository. I think there would be an immediate influx of 0days as people find holes but I would hope they would close quickly. It's still a very big gamble to let go of something you've literally built your foundation on but I do hope that instead of Windows silently going into oblivion that they'll open it up for the masses, even if they would no longer have the resources to support it. I feel like someone or company would step up.

Having said all that, I'm going on 4 years in mostly macOS. The missteps in High Sierra are pretty abysmal but not the end of the world. I hope Apple really changes their processes to keep the OS stable but I see this downward trend in just about all PC-like operating systems. It's like everyone sees the end of the line coming and they're just half assing every move they make. I think Meltdown/Spectre was a major blow that has probably single handedly slowed all momentum to a standstill. Granted my sample size is very small but I really hope I'm just looking at this big lull right before an evolution/revolution.