They didn't program anything. They gave it data at best.
>The idea has not been taken very far, so what is there to scale?
LeCun was the head of Meta AI for over a decade and his baby that he keeps harping on about wasn't taken very far ? Come on. You're smarter than that. It went the way all the alternate architectures have gone since the transformer, a sidegrade at best, probably not even that.
>You might compare with Uszkoreit's initial poor-performing implementation of his new language model architecture - should he have given up?
What are you talking about? There was no poor performing implementation of transformers that was published that he needed to push through. Are you talking about self attention experiments before the finished transformer? That's literally just research. And if he languished on that for a decade then yeah I'd tell him to probably look at something else, but of course he didn't.