It's sort of a deterrent from "herd immunity", but it's mainly so that if a crime escalates from property crime, you can defend yourself. I'd toss my wallet/cash/etc. in one direction and move to cover/flee/draw, depending on the circumstance. I'm fine with losing whatever cash/credit cards/etc.; I'm not fine with being under the control of an attacker and potentially moved elsewhere, taken to an ATM, kidnapped, shot, etc.
The bad thing about CCW is it turns any assault into a likely-to-end-in-someone-shot situation; if you're carrying and potentially will be knocked unconscious in an assault, or are being grappled, the attacker may grab your gun and shoot you; your correct course of action is to shoot him first.