most of your examples are of wildly successful musicians on a global scale and lending/endorsing their name/ownership to a business just adds to the credibility/marketability of that business.
I take your point to some extent but they were all heavily involved in the business side of things, hence the examples, and in Anderson's case he was instrumental in setting it up for additional income/security and tinned salmon isn't exactly a sexy, rock-and-roll thing and I am not sure being a rock star would have helped brand recognition much, although I did first notice Newman dressings due to his picture on the bottle (but I kept buying because it's decent and if not his picture would only have got one extra sale from me). There are plenty of examples of what seem to be endorsement too (clothes, headphones, etc.)
Being wildly successful gave then the capital to set up what they set up, so you are right on the money with respect to that, but my point is more that at a lower level there might be more modest business investment opportunities that give a backup plan, in the event of music not working out so well, or carpal tunnel syndrome curtailing a career, for example.
