I was one of the ones trapped on a plane for 5 hours. Frankly, I think I had a better deal than the ones inside. The terminal we eventually made it into was the only one with any lights on, and after waiting on the tarmac for 5 hours I was suprised to find a crowd of people inside that still thought they were getting on a plane eventually.
IMO Delta employees did everything they could to help the situation. I was very unimpressed with the airport itself, however. The whole place needs practice in disaster response. No one knew what was going on, there was zero visible coordinated effort and a lot of various agencies present trying to solve the problem but unsure exactly what the master plan was. So as a result you had EMTs huddling around persons in wheelchairs, ATL police mostly just keeping the peace but with no answers, random personnel screaming to evacuate because of Fire Marshall orders and then more random airport personnel screaming don’t evacuate...as soon as I left the plane I knew my family was on its own and we had to make our own decision. We decided to leave and get a hotel-but thousands of people all trying to evacuate at the same time with minimal plan or direction is a beast in and of itself :-)
Those that were good at making plans on the fly or knew how to use technology to quickly book a hotel and find transportation like Uber benifited from those skills. It was interesting to see the normally very controlled environment devolve into basic human needs: food/water, shelter, transportation. The crowds were very unsure of what to do when all the personnel giving orders and direction suddenly stopped doing so.