You know what they need to do to quell everyone's angst? Is publish the age of all the people calling in sick, and then run the statistics against any other company that has the same age demographic. And if statistically there is truly a bump in Delta sick usage as compared to all the other companies out there that have the same age demographic, then they would have a leg to stand on. This of course would have to take into account only the sick call itself. And not the drop of a whole trip etc. etc.
I remember in the Air Force, they had this whole thing on sexual-harassment. They beat us over the head and said that the Air Force is awful right now, we even got spoken down to buy some 28-year-old lady from the state telling us how bad we all were as men. And then with a little research we found out that the USAF was right on par with the national average regarding the age of people and amount of instances of sexual abuse.