Well, Bret Victor presumably isn't rich rich.

Some ideas—key novel concepts and conceptual frameworks, for example—absolutely have value, but they're not valuable in the way a business is valuable. You won't become business-owner rich just by coming up with the right concept, but you can have a successful research career, get enough funding to run a small research group, win a Nobel/etc prize... etc. But that says more about how our society and economy are organized than it does about the inherent value of ideas qua ideas.