This (and Andreessen's article) is quite insightful of knowing when you're on the right track or not, but it's more like a "you know it when you see it" kind of advice that is not very helpful in terms of how to get there, or how to design a process that allows you to methodically identify and jump into these market opportunities. Maybe a second article could dive more into that.
I agree with your point 100% - if we could tell you how to get there we would! I think the biggest point is that many companies die because they scale expenses as if they had reached product market fit when they haven't. We are trying to give you more time to find the right problem/solution.
People tend to say the same thing about marriage. They say "when you know, you know". Not extremely helpful information. However, you can optimize for that scenario by dating as many people as you can. If you go on 3 dates a week for 6 months, thats 75 dates of worthwhile info you can use to get closer to that objective.
