There is also an article in the Telegraph. It mentions that MPs think that there are about 150,000 homes where it is not financially viable for private companies to connect them.
As I understand it, it's actually 15-20% of the UK (i.e. about 5 or 6 million properties) where it's considered not financially viable for private companies to connect them without government subsidy. That's where DCMS is supposed to be focussed.
Of those, there are about 150,000 homes where apparently it's not financially viable to connect them *at all*.
It's unclear if those 150,000 homes already have copper connections. If they do, it was achievable to connect them in the past, so why not now? I expect it could be done for a fraction of the cost of HS2.