Fast internet is a complement to Google's services. It's in Google's interest to commoditize fast internet. They're not interested in offering Fiber, they're in

Fast internet is a complement to Google's services. It's in Google's interest to commoditize fast internet. They're not interested in offering Fiber, they're interested in making the internet faster and cheaper, since that helps there core business. So their Fiber investment was the lowest they could get away with to still make other players believe that they just might be serious about it in 2015.