A credit score is used as a trustworthiness analog in arenas other than lending. For example renting a house or car, and some phone companies won't give you access to a post-paid plan, all of which can have a stratifying effect. The idea that because I don't take on debt that I am not trustworthy is wrong. I can pay a larger security deposit to offset risk, but often times that's not an option.

I've also heard tell of employers using credit checks to evaluate potential employees though I haven't researched that.