Except that it's a terrible idea. Why would you take billions you make from doing work at a 30-40% margin and blow it buying a business that returns 5-10% margin at scale -- but only after 5-10 years of cash flow negative investment? Wouldn't a better idea be to invest in businesses that could potentially return 20% and are closer to your core skills as a business?
Google has many skills, but last-mile delivery networks aren't one of them. Not that they can't be, but it's just not that profitable of a business to waste their time on. The business itself is just a math problem balancing quality of service with investment -- and not a particularly difficult one.
Fortunately, that's not their play here: Google has invested far too little money in Fiber to be truly serious about it as a business. Fiber is just their way of generating consumer demand for higher speed pipes by saying "hey, look at this! this is how it should be!" They did the same thing on Android with the Nexus phones, so it's not even a new tactic for them.
> Google can eat a lot of the costs of setting up a better network, which is a great investment in the future if you're betting that a majority of people will need high speed internet access 10-20 years from now.
The problem is that you can't just build the network and be done with it. It costs a lot of money to maintain and provide service (approx. 10% of the original cost of the network per year), and that's money that Google will want to spend on other, more profitable things. Hell, if they want to get into infrastructure, the smart play would be free wireless Internet for the developing world (i.e. what Facebook is doing).
But again, Google hasn't spent anywhere near the amount of money on Fiber that they would need to in order to make it a commercially successful business. Because that's not the point: they're using cities like Kansas City and Austin to showroom their vision of what the Internet should be.