Why...? It's obviously a tool to spy on their citizens even more effectively and very possibly to spy on western citizens as well.
I'm all for alternatives to Android and iOS, but I'd rather be spied on by private companies than a country that pretty much plans to take over Asia and then the rest of the world in the coming decades (well, in my wet dreams SailfishOS matures as a real alternative and I don't have to choose Android at all).