Planning ahead wasn't the issue. The issue was rationality, or economics if you want to call it that. You don't want to build out infrastructure way in advance of demand, it's just bad engineering and would have imposed huge costs on the already crippled British economy for no gain. In the period we're talking about home computers don't speak TCP/IP at all, there is no web, the highest bandwidth users of the internet are email / IRC, hardly anyone is selling internet access to homes and the biggest sites have uplinks of a few megabits/sec at most. What exactly are they going to connect to over all this fibre? Online video wouldn't become practical for decades, machines of the time couldn't even begin to handle it even with infinite bandwidth.
No, Cochrane was an idiot, exactly the type of central planner privatization was good for getting rid of. Look at what he's saying.
> In 1986, I managed to get fibre to the home cheaper than copper
According to a guy who hadn't done it. How do you make building out an entirely new physical network cheaper than using the existing one? What was this magic trick he found that let him snap his fingers and instantly replace all the wires in the ground? That claim just wasn't true, was it.
Lots of things in that interview were very wrong. "In 1974 it was patently obvious that copper wire was unsuitable for digital communication in any form". The first patent for what became ADSL was filed in 1979. Internet access was rolled out across the existing copper network successfully for decades after that. His engineering skills were "obviously" not that great because DSL isn't an unintuitive idea, it just runs data at different frequencies on the same copper lines as voice. There were high bandwidth copper links in the 1970s already. There's lots of details involved to make it work well to consumer residences, but the concept is simple enough. He didn't research that possibility first because being a nationalized monopoly meant there was no downside to just playing with the coolest tech whilst ignoring economic rationality. He had no history of running a profit-making business, he'd spent his entire career in nationalized monopolies.
You can see the problem here:
> "It's like everything else in the electronics world, if you make one laptop, it costs billions; if you make billions of laptops it costs a few quid".
Since when do laptops cost a few quid? And the costs of FTTH aren't dominated by the cost of fiber and switches, WTF. The cost is all in the manual labor of rebuilding the physical network and upgrading the homes themselves. You can't manufacture your way to a cheap nationwide fiber network.
This kind of economic illiteracy is exactly what brought the British economy to the edge of total collapse in the 70s and caused voters to bring Thatcher in three times in a row (and maybe they'd have gone for a fourth if the Tories had let them).