Oliver was saying it was silly to ask for a credit check for firework selling but looking on Criagslist they advance you the tent and stock and then rely on you returning the unsold stuff and a percent of the sales. There'd probably be a higher chance of someone with bad credit running off with the stock.
Being advanced stock is literally being given a loan of that stock, and the primary motivation of credit scoring is to be able to judge whether someone will default on their loan.
Admittedly, that only defers the question to, "Does credit scoring accomplish its primary motivation?" But you could become a loanshark millionaire if it turned out that people with low credit score were equal or better borrowers than people with high credit score, since the existing financial industry isn't serving them as well.
You know, there's a degree of uncomfortable truth to this that requires the words "common sense" to be thrust between quotation marks for the statement to work.
