You're acting like PG is sitting on something profound here, but there's nothing profound in the slightest. Nobody has ever gotten rich writing financial statements, they get rich by creating value that didn't exist before. The financial statements don't get you customers, don't build revenues, don't develop products, don't manage your cash flows, and don't manage expenses. But they're still crucial because they communicate, in a fairly standardized way, all of the most important measurements of a businesses success...including the three things that you just said PG cared most about.
Telling people that financial statements don't matter is like telling a PhD-candidate astrophysicist that it doesn't matter that they can only communicate in Azerbaijani as long as their physics research is rock solid. It's already completely brain-dead obvious that the physics research quality is the most important thing...but it's a breach of duty to tell them that they don't need to know how to communicate it to their peers.