Surely that is what BT are doing now with FTTC and FTTP, the start of a complete fibre telecoms system, and the best part is they are effectivly getting large sums of money to upgrade some of the network, where they get BDUK funding. Then with FTTP on demand even the customers will be directly paying towards upgrading the network.
Eventually they may gradually upgrade more areas to full fibre, bit by bit spreading that massive cost out over the years.
When I'm being positive, I have exactly the same thoughts.
When I'm being even more positive, the FOX exchanges are a distinct pointer in exactly this direction - allowing BT to aim at removing the cost of the exchange building. It's almost a roots-upward 21CN using fibre.
But when I'm being negative, I wonder if this is all something of a dead-end, like TPON. Both aspects get questioned on scale...
Will the technology deployed for Fibre-on-demand really be able to cope with every house in the area (eventually) being swapped onto GPON fibre? Will it truly give everyone future-proof speeds?
Will the ad-hoc deployment of fibre - to individual "rich" homes on demand - really lay the groundwork (splitters, manifolds, ducting, etc) for future homes in the same direction to be easily connected? Will the ad-hoc nature ever lead to a "planned" network?
The FOX exchanges are the other way around: Will their planned nature be affordable? Will it lead to widespread deployment?