Peoria has an annual Rib Fest competition each fall with similar rules.  Among the other rules, they specify, “Selling or giving away your ribs to the general public is prohibited unless you are a registered vendor.”

I have never bothered to go downtown and see it, for much the same reason as what you mentioned.  (Why try to learn their technique if you can’t taste their results in order to see if you like it done that way?)