I agree that credit scores are stupid, but for the purpose of playing the devil's advocate... Person A may have just crawled out from under a rock (or their parents' money) and knows not how to manage a credit or just thinks it's free money. They'd still have no credit history. For risk assessments, you always take the worst case in all fields where it applies, not just financial.

On the other hand, I think that if your circumstances change and you manage to pay off a loan early, you get penalized on your credit score, cause some bank had plans for your interest for the next 30 years or something.