I understand that hard credit checks negatively impact a person's credit score. Why would it work this way, because it's seen as a negative thing to be applying for credit cards too often? Even then this is not necessarily a bad thing if the intent is to determine how likely they are to pay something back.
If negatively impacting your credit score is the only difference, then why not just use a soft credit check? Is it that a hard one is more detailed and thorough?
For context, I heard of a credit card that if someone isn't eligible for it, they do a soft credit check instead and approve them for another version (where an initial deposit must be made).