First, I am relatively agnostic on the whole OC issue. In fact, when OP posted the original link to the news article, I contemplated a snarky comment that one incident is not data. The snark side is seductive. Anyhow, OC is not how I would choose to carry, but I don't like telling other people how to act. As long as OC'ers don't create a backlash against public carriage, I don't have a dog in the fight.
Second, we can try to be in condition yellow whenever we're in public, but inevitably we will have lapses. Moreover, criminals almost always have the advantage of choosing when and where. That's a huge advantage - especially when you consider how poor your vision is in the rear of your head.
By openly wearing a gun:
1) The OCer will dissuade some criminals from engaging in criminal conduct;
2) The OCer will surrender an element of surprise;
3) The OCer will encourage some criminals to engage in criminal conduct
4) The OCer will encourage criminals who choose to engage in criminal conduct to up their game (both strategy and level of force).
You can (and should) come up with your own list of factors. You might arrive at a different conclusion than me. I'm fine with that.