I’m no AA apologist, but I’ve said this before.... in over 30 years in and out of PHL (never connecting there), I’ve had a tiny number of issues with delays within the airline’s control, bags or customer service even though I tend to avoid much interaction with staff because I prefer to just handle what I can by myself.
Yes, until around 7 years ago this was US Air/Airways so it was a different company and culture pre merger. But I’m betting most of my exPHL crews I get today are legacy US crews and they’re mostly good. These past 2 months I’ve given out more A&B certs then I did the entire previous year!
You're right that it’s a huge airline (biggest in the world) so you seem to have run into a few bad apples who missed that day of customer empathy training. Only you can decide if it’s worth giving another shot and encountering employees who are a little more warm.
I have the same experience and transition from US Air. Most of my routes go through PHL and most crews are legacy US crews. My five years with AA have been great overall. During the merger there were computer issues with reservations, plane substitutions, etc but that was a few months. Occasionally I may encounter a delay but never any of the crazy scenarios people here on FT report. All my nightmare experiences with air travel have been at the hands of DL and UA (former Continental) going back the decades over which I flew with them.