Here's something that hasn't been mentioned, it's tougher to get vetted, and into the military, than it is with a regional airline. That just means the odds are slightly better that the guy doesn't have any significant skeletons in their closet.
A significant portion of the hiring process is risk reduction - improve the odds that the person being hired isn't a mistake. Otherwise what's the point of psychological testing? And yes, it's amazing that some of your/our coworkers passed the pysch exam. What the heck are they looking at, or for, if they got hired!?!?
If you think AA, and perhaps DL, isn't hiring a diverse group you're not paying attention. Of 109 new hires this year a minimum of 16 (15%) were minorities when the industry is 9-11%.
The flows are taking approx. 63% of the training slots. If mil guys take 80% of the OTS slots the military percentage of the overall hiring is 30%. The military didn't take the slots you'd normally be competing for, instead the company made the decision to get their civilian pilots via flow agreements.