I think that Microsoft is paralyzed by corporate culture. Everything needs to be signed off by multiple stakeholders, everything needs a dozen meetings before anyone can make a decision, and as a result the stuff that's "good enough" (read: still making money) languishes--or worse, becomes a dumping ground for whatever corporate pet project is exciting--until it's unacceptably awful, mired under decades of technical debt and spaghetti code fixes.

At least they have the sense to let the successful companies they acquire manage themselves. There's no AI in Minecraft, for instance.