ATL was in a ground stop about half the day.
The “new” SWA cancels flights at the drop of a hat if they think there is a chance of bad weather affecting ops. Some accountant has figured out that it looks better on a spreadsheet to just reaccomodate pax later without all the delay drama and ensuing and cascading delays that last hours in a station where you are constrained by gates (ATL). Delta has the infrastructure to handle the ground delays. SWA would just end up leaving the pax sitting on the ramp waiting for a gate. HQ has made it very clear that a tarmac delay is an unacceptable outcome. Note also that SWA is about 40 airplanes short right now, so freeing up aircraft is also a priority.
I personally don’t agree with it. I think you lose a lot of customer goodwill and it is left to the crews and ground ops to try and explain it to ****ed off pax, but it is what it is.