I don't think they actually have much choice, what else are they going to do....give up on mobile?
You know what? Yeah. Yeah, they should. Because they've been banging their heads against the wall trying to make it in the mobile computing market since
1996, and in that time the most you can say is that they had some moderate success with Windows CE back when "pocket PCs" were still a thing and every PDA/phone OS was horrible so it didn't really matter that CE was horrible too. But they missed the boat on modern smartphones, they missed the boat on tablets, and the best they've been able to achieve in that space is Windows "well, it's pretty okay" Phone 7/8, which still hasn't even come close to touching iOS's market presence, let alone Android's.
CE is dead. Nobody wants Windows Phone. They botched the Surface line and nobody cares about it anyway. And all the while they've been alienating their real customer base trying to force themselves into the mobile market by trying to make all their desktop/laptop users use an OS designed for tablets on the theory that this will get them to replace their PCs with tablets. Enough of this nonsense. They need to throw in the towel on this, go back to focusing on their strengths, and let the mobile market sort itself out, not double down on their flailing and failing attempts to be a third-place also-ran in a market they long since missed their chance at.