"The one place where the investment generally wouldn't be needed because the upgrade is likely to quickly become self-financing."
Actually you would be surprised. The BT Tower is literally at the end of my street and we have no fibre deployed anywhere near us by BT, with anyone wanting more than ADSL2 needing to go over to Virgin. Sadly Virgin has largely treated our area poorly (being the monopoly) with many of the local nodes well oversubscribed causing congestion, especially in the evenings.
Last time I wrote to the BT Chairman to find out what happened with our supposed FTTP rollout (the leaked original plan was for sometime around 2013), I was told that in order to get fibre to our area, we should apply to the rural broadband fund. Needless to say I have left a copy of the letter whenever I require a good laugh. The end result is that central London areas are poorly served by providers. BT is simply not interested, which then means we can't even go to a provider who uses BT copper/fibre. Virgin whilst thankfully has improved in the last few months (and we are literally talking only a few months) after years of the network constantly going down due to poor signal levels and noise added to the local network nodes being oversubscribed. Virgin therefore acts as a monopoly which means generally the service is poor as you have nowhere to run. Relish broadband is available in our area, but as anyone in Central London knows, their service is poor at best (which is a real shame).
With the above in mind, having a real fibre option would be nice to see.