I think there's also some Conservation of Thought (1) involved-- if you have a credit history to be looked at, there are Actual! Records!. If someone is just solvent and reliable and has a good job, then you have to evaluate that.

There may also be a weirdness factor if relatively few people have no debt history.

(1) Seeing Like a State: How Certain Schemes to Improve the Human Condition Have Failed is partly about how a lot of what looks like tyranny when you're on the receiving end of it is motivated by the people in charge's desire to simplify your behavior enough to keep track of you and control you.