I think he's saying it took a life of its own and its incentives are destructive to mankind. I disagree but I can see how you could make the argument, supposing you think bitcoin has no use / value and that smart contracts are just a fad. But maximalists have their own arguments regarding the use of blockchain and while a lot of the rhetoric isn't believable I do think blockchain tech will be +EV in the future even if most don't believe it already is.

Basically it is a purposeless algorithm that saps resources for useless computations, that is only interesting insofar as it can sometimes perform sophisticated optimizations albeit in pursuit of a trivially useless goal.

Zoom out and think of the entire blockchain algorithm at a level above the incentives of a singular agent.

It's very much like having a superhuman Paperclip maximizer that has a invented amazing techniques of say, iron ore extraction but this localized advance is squandered in pursuit of an absurd goal of creating the maximum possible volume of paperclips.

Of course there is not a single agent on earth who pursues bitcoin mining with the goal of wasting energy and compute resources but it is the aggregate end result. Bostrom similarly argues the the objective function of a complex system such as an AGI may drift entirely from its original intent leading it to optimize for things we absolutely do not desire and this malignant drift is an emergent property.

The similarities to blockchain are uncanny.