This interview took part when the economy in the UK and USA had hit the skids, while the USSR's economy was chugging along like gangbusters. In fact, a significant number of English and west European workers moved to the USSR to work since there was a labor shortage. American firms went there as well.
Whatever the economists were talking about, the US had just started to change to an incredibly centralized, semi-planned economy based on military spending as well as things like the NSF. The US is still like this, the military budget is over half a trillion a year, and the brass has been publicly begging Congress for decades now to not make so useless tanks and such. It is a job and research program, it in/directly financed the transistor and IC and microprocessor, it created the Internet and so forth.
Under Stalin the USSR's economy was doing great. Khrushchev made a lot of changes, and problems began cropping up (bread shortages, less capital spending etc.)
You can't make a comparison with the US as an unplanned economy, since this was the beginning to changing it to a semi-planned economy with a (conservatively) $600 billion a year "military" budget. You can't say Stalin's economic policies failed, as they were successful under himself, and Khrushchev majorly changed them in the same way FDR changed the US policies.
Also the price argument is tautological and not falsifiable. Something is valuable because something is valuable. Let us say that Bitcoin is a giant Ponzi scheme (which it is), a $6 billion bogus market cap of worthless hashes. In fact it was a $14 billion market cap four months ago, now $6 billion. Is all the equipment buys, and wasted electricity and so forth a rational allocation of capital? Couldn't it be better used to make something useful? Well it's a rational allocation because of the price which makes it rational which points to the price. It's a circular, tautological, unfalsifiable argument. When Bitcoin's market cap crashes below $1 billion, and then lower, the price argument you mention won't have its defenders admit they're wrong because it is tautological.