It's not nonsense, it's an obviously-tautological statement, made with the full awareness that it's not helpful advice, but used to explain the point. It's one sentence out of a long essay. Later in the essay he provides recipes for coming up with startup ideas, even though he warns that that approach is suboptimal. What more could be asked of him?
It's not empty, it's just way, way! too politely phrased. It's not advice on how to find ideas or how to become that person, but advice on who is ready to give founding a startup a try.
During my career I did freelance mobile app and web development for about 10 years.
In that time I came across many people who wanted to found a tech startup because "that's where the money is" and being a tech startup founder being a status symbol. Some enthusiastic youngsters, but mostly people who had a successful non-tech small business. And they were not the right sort of person and did not have the right hunches, they didn't use what they learned from their non-tech business, but instead sat down over a beer with friends to brainstorm "social-local-viral" app ideas.
The advice instead should be that if you are struggling to come up with startup ideas, you probably aren't the right sort of person at this time. You should do something entirely different for a while until you find a product that just has to exist.
Unfortunately, they had never read HN or PG, nor could I do more than politely refuse their business.
You can't use the criterion: if it is insightful it has to be actionable on an insight that says "I have no actions for you".
The difference is, it is not trying to trick you.