I mean, it could just be a clever allusion to a mall. And spotting a trend and jumping on to monitize is pretty straightforward. He just never found a way to ease the friction, and google pay remains a reletive novelty here. Compare that to china, and you may realize there is, still, an great untapped market for such a service. The failure was not the stupid SV thinking, but inability to execute successfully. Given that Apple, Google, and others have tried similar, it is no huge failure imho.