Microsoft realizes the end of the PC-era is here. (Almost) nobody is buying PCs and OS-licenses anymore, so Microsoft can't gamble it's future on those petty things.
They realize that the future belongs to services spanning several devices and multiple platforms, among which Windows can be one player. That's why you can have Microsoft-software for iOS and Android these days.
But for Windows to be a player in the future, people must want to have it on their shiny, portable touch-devices with long battery-life due to apps running in a controlled environment.
Nothing from the desktop-era Windows fits into that picture. Nothing. For Microsoft to be on those devices that just needs to go.
You and I may hate it, but Microsoft is literally forced to make this "new" Windows-model if they want to remain relevant in the future. Microsoft is upping its service-game, and it will do so at the cost of everything the PC used to be.