"Linux could use some Google attention" -- I'm not sure if you noticed, but Google has been giving Linux its attention for the past 14 years.
The people who don't need desktops or laptops are already using ipads and Android tablets as computing replacements. They get their web apps and that is all they want. To write emails, they might get a bluetooth keyboard. To write a document, they might use google docs. They have no use case for a full sized x86 desktop or laptop anymore.
Meanwhile, productivity software like Photoshop or Sony Vegas is completely off the table for Android. Both depend on directX, and unless Google outright bought Adobe or Sony they wouldn't persuade them to rewrite the whole thing to port it. That stuff won't show up on Windows RT either, even though porting with DirectX intact would still be easier than porting to openGL. Same thing with old games.
If Android x86 or just desktop ARM were put in stores tomorrow, no one would buy it. Gamers would get Windows for games, artists would get Windows for photoshop, grandparents would still buy tablets because they don't need a desktop, and businesses would still get Windows because all their shoddy business applications were written on Windows.
By that logic wouldn't we all still be using series S40 Nokia phones and Windows laptop?