This is the future; partially fuelled by malware, partially fuelled by the desire for platform control, and partially fuelled by government regulation.
They tried to pull a similar move with WinRT/UWP, but nobody wanted it, so now you can continue with Win32.
They would love to do so, but legacy compatibility is a major business advantage.
They did a bunch of terrible inept rollouts with confusing technology for both users and developers and effectively shot themselves in the foot. But it did not have to go down that way.