Making it a moving target they can't hit would be a lot harder a few years ago when customers were more demanding of new functionality.

These days people are less keen on upgrading on every iteration than they used to be and are happier using older kit for longer. If they upped the maintenance window, in fact, that would force google to compete even more fiercely coz users would have to really really want the new features.

I, for one, would vastly prefer using this over the latest android even if it lagged a couple versions and cost a bit more.