I mean, I get it, but isn't it also just a little ridiculous to think that someone lending money would not legitimately want to use a measure of creditworthiness, which might have some correlation with age?

Credit score (or credit worthiness) is an indicator or reflection of how likely someone has been to pay his/her debts over time. You want a measure that indicates some track record to not have any correlation with someone's age? That's almost as nonsensical and headscratch-worthy as the job listings that ask for 5 years of experience in <xyz> for an entry level position.

Sometimes trying to be so fair, you throw intelligence out the window.