That's factually wrong. He is also a co-founder of OpenAI, and within YC, he initiated YC Continuity (just to name one of the many initiatives that continue to live on). So if you're specifically evaluating him on finding the PMF within his own projects, I think you're not giving him enough credit.
If we were to evaluate him against his investment record, the score looks even better - he's clearly a wealthy guy, and it appears that most of his pre-OpenAI money comes from this area. This is significant, since if he can spot a good startup early on, then supposedly his thoughts on early stage startups are likely valuable.
You might go ahead and trivialize those data points, but the reality is that's a 100x better resume than the majority of people whose blog posts form a basis for daily discussions here on HN. Why hate on Sam specifically?