For lots of people, because that would cost them all their other Google accounts and services. The OP would have to give up on Android development. I am forme

For lots of people, because that would cost them all their other Google accounts and services. The OP would have to give up on Android development. I am former Fi user, started back when it was a "Project". My Nexus 5X's battery swelled but was still working and had a full charge, they wanted me to ship it back to them which I morally felt I couldn't do, and replace it with a generally low quality Lenovo Motorola phone that was reported to have serious WiFi problems, negating that major part of their business proposition where it uses any accessible WiFi for data and voice if possible. Felt stupid for having paid them $5/month for device replacement coverage. The G+ real names debacle prompted me to remove as much exposure to Google as possible, now I'm down to Google Groups which can only be had from them. They're just too risky for individuals to depend on.