The actual reality is that starting a company is very complex, and for every “rule” there’s a very successful company that did the opposite.

If your takeaway from this is that “build it and they will come” is a good go to market strategy, you’d be terribly wrong in the vast majority of cases. It worked in this case because it was a solution to a painful, concrete problem and the product hunt audience happened to be the right customer suffering from that problem.