Well, this plus the psych profile Delta is looking for has worked exceedingly well for the last 80 years. Sure some make it through, but the vast majority fit a certain profile that the company is looking for. Why, you ask? Because they can.

I would then suggest don't apply to Delta because that is exactly the basis for how you are going to be evaluated. Walk in angry with a chip on your shoulder, and the outcome is a certainty.