So, rather than laying fiber, which is relatively cheap to buy/install and incredibly cheap to operate, you want to replace all the phone lines with one of the most expensive metals around (copper) just so that you say "fiber is a waste".
The benefits of fiber are huge - you can use passive optical splitters that use no power and require almost no land, and it'll serve 30-300 end points using GPON. Over this single fiber, you can serve on-demand TV, internet, phone and security alerting, with efficient use of multicasting for the live TV and unicast for everything else. What's more, you don't have to supply voltage down the cable, wasting lots of energy to the environment, it doesn't corrode or degrade (to a large extent) and at the head-end you can fit literally tens of thousands of endpoints into a cable no fatter than a single twisted pair connection.
The benefits of copper are: You don't need to power it at the home, so if the power goes out and your battery backup unit has failed, you can still make an emergency call. That, and the line is already present.
Pretty simple choice, really. If the UK Government were really committed to investing in the future of broadband in the UK, they'd lay fiber to every street cabinet *now* and prepare to get the local councils digging up the capillary roads to lay a fiber alongside Virgin Media's cable, starting within 5 years for eventual turn-on by 2020.
The biggest bottleneck in broadband speeds in the UK is the copper. It's nothing to do with the low upload speeds, which are only present because it makes a lot more sense to divide the spectrum on the line weighted to the download speed rather than the upload, which is very rarely saturated - unlike the download.
The second bottleneck is that when the signal terminates at the exchange, it's backhauled over to an LNC in London inside a PPP/L2TP header and (usually ATM) cell-switched, rather than IP(v6 eventually) routed. That would kill the broadband market, however - essentially making broadband a public utility rather than an a private ISP service. Knowing how bad BT run things at the moment (especially when it comes to 21CN etc) that can only be a "bad thing" without clueful ISPs bashing them all the time to fix problems.