I'd still bet that the majority of people who have a belief that meets all the criteria you suggest are probably wrong about that belief. For example, I think there's a reasonable case that most priests' religious beliefs would met your criteria, and it's clear that most priests are wrong (as long you you take priest to include holy men from all of the world's religions, it must be true).

I won't speak to the usefulness of the quote as a means for generating useful entrepreneurial ideas.