Perhaps because with existing emulation you don't (easily) get the play services, with this you will easily be able to pay for microtransations to "win" in your games and google gets their 30% cut of those. Its also easier so more people will use it and pay to win. Perhaps it also gives them more data on their users since they can directly snoop on everything running, connected to or stored on the Windows system, play store services running on an emulator is less useful to google.