Inventors, some of the most important things we use today were made by people who never got a college degree (and in some cases not even a high school one). Can't say the same for most business people or physicists.
Can't say the same in which regard? Education? Because the study of physics generally necessitates higher education these days. Business doesn't necessarily require it, but it gives you an edge the same as it does inventors. And, in general, a lot of the inventors who never got a degree often did so before higher education was readily accessible. However, you have tons of inventors who were college educated.
If you're talking about the things we use today, half the reason we have those things is because of businessmen. The availability of goods and services within a society is largely dependent on commercial enterprise which falls into the realm of business. You need a manufacturer to make the items, a wholesale distributor to buy them, and then a retailer to carry them -- assuming that the retailer doesn't function as an all-in-one, such as in the case of Apple. (And, depending on the product, physics might be involved.)
All the business man does is see a good idea that has already been done and market it, while the inventor sees a problem most people don't think exists and creates a solution to it. While it is true that the business man usually gets all of the credit *COUGH*STEVEJOBS*COUGH*, inventors really are the people who have done all the work and should get the credit.
Anyone can become a business man or a physicist with the proper education. That can't be said for inventors. It is an skill that can't be taught.
Except you literally can teach people to be inventors. Hell, there are whole courses in product development available at colleges and the concept of product development is fundamentally a business idea. The problem might be that you're thinking in prehistoric terms where creative work was done entirely from the gut -- be it an invention or ad campaign -- instead of through market research, focus groups, and a generally more scientific approach.
And, given the nature of invention, it's easier to be an inventor than either a businessman or a physicist. Especially since many inventions are just improvements on older inventions. ---