Obviously, "success" is real. We can say very clearly that some people are successful, some products are successful, some projects are successful. But "success" isn't a unified thing that you can teach. What makes it possible to be successful in a given domain is different in different domains. To be successful in a foot race and to be successful in stock trading require very different skills, such that you can't teach a "success" class that will make you successful at both a foot race and as a stock trader.
And further, in a lot of endeavors, being "successful" requires not just particular skills to that endeavor, but a lot of different skills. Making the iPhone successful was about manufacturing at scale, software, hardware, marketing, supply chain management, contract negotiation, etc.
Let me suggest that "design" is more like success than it is like math or reading. A product can be well-designed, but I'm dubious that there are unified "design" skills, especially ones that translate across a fairly wide domain. What makes a product well-designed is much more diverse than what people who talk about design typically admit, and I'm not sure that design as a field really makes any sense.