That is indeed a better criticism, but it happens to follow the same template as another common startup criticism: "It hasn't been tried before, so we don't know whether it will work."
Yes. That's true. It might not work. And you're probably even correct. But that's always true, and the most valuable cases are those that work when most people don't expect them to. http://paulgraham.com/swan.html
You say that every other VC does this. But if other VCs are training ML models, they don't seem to be publishing their results, so I'm inclined to say that this is new.
Is it going to work? Well, we'll have to see. But as with most startups, the answer is "probably not, but the chance may be significantly better than random."