In my experience, there's always a group of people who'll cling to older technology with much vigor. This could be for many reasons including financial, though for DSL to FTTP, there's also the loss of ability to spend time monitoring line statistics and tinker; something that many have grown used to enjoying and committing much time to. FTTP is superior in every way, though a child has the same proficiency in connecting to it (via ethernet or Wifi) as someone who is an expect at xDSL line statistics/modem manipulation/confguration. There's an element of "letting go" that will cause some to cling onto their xDSL until the bitter end.
This is why the project to completely strip out the copper network, forcing everyone onto FTTP, is so important. Luckily, as the country's finances are in shambles, I highly doubt the government will give BT the billions it would need to extend the life of the copper network, even once we get more people complaining of lack of landline use during rare power outages in the most remotest of rural locations in the UK. I do think they should get a large government subsidy to supply larger batteries to such rural locations though, to keep these people safe. Really is no excuse then.