My comment would still apply if these were the first flights of the day to arrive in ATL...regardless of the fracking thunderstorm. I am not arguing about whether anyone wants to fly in a fracking thunderstorm. DL will sequence however they please and damn the passengers to any other mechanisms, basing it all on the original ATC/Wx reason for denying any/all compensation claims, even if they add many hours to the flight beyond the SPECIFIC delay caused by flow control.

I have been on a morning flight out of BWI where the original delay was due to ATC/Wx at ATL. Once the hold was cleared and we were allowed to board, the pilot found a dead fire extinguisher in the starboard engine. The flight was eventually canceled (after DL took three hours to determine that no other airline at BWI had the spare parts in inventory to assist), causing many of us to miss the additional, and in some cases final, connections to our original destinations (in my case, resulting in a total of 8 hours of lost time). The compensation for our delays - absolutely nothing; DL BWI stated that the original delay for the flight was ATC/Wx,despite the later admission of a mechanical cancellation, so they have no responsibility other than booking us on the next available flight.

The comment is hardly uninformed, unless personal experience fails to count when informing oneself of an opinion. It may not be entirely correct in this SPECIFIC instance, but perfectly valid in other instances of similar type (I don't think the OP's posts limited answers to just these two specific flights).