I guess I don't see the "Google or nothing" aspect, except that no phone maker other than Google (Nexus) is currently offering the hardware that helps it all work seamlessly. I'm sure Google expects to profit in the long run, of course, but I think they are trying to create a demand for phones that can do these sorts of things, regardless of brand name. A "rising tide lifts all boats" strategy that helps everybody by making phones more usable overall.
The lack of similarly capable phones from other brands kind of indicates what the cell phone industry thinks of the idea, though! The carriers are all still on the "exclusive marriage" business model, trying to tie us exclusively to their one network. They fear that metro area subscribers could too easily exist on wifi only and might not want a carrier plan at all, or only a minimal one. This idea isn't gonna fly until Verizon, AT&T, etc. can see a way to make money doing it.
I don't have a Nexus phone, so I can't use Project Fi. And from what I read, the wifi-to-cell-network magic works only on T-Mobile (so far). Another strike against me as a Verizon user.
