Bubbette
No, the reason I compared the 2 was the fact that with both airlines having hubs in ATL, there is a relative route "overlay" for cities served, offering a direct comparision.
If I wasn't clear in my previous post- I apologize to any Delta flight or cabin crew- no reflection on the safety of your airline.
Reasons for not flying them lie are varied, service oriented, and not related to safety. I'll guess they're off-topic and don't belong here.