Well, MY experience with United Airlines was most excellent.
We flew out of ORD to England and back. When we arrived at the airport, we were early, but I enjoy big airplanes and I had a good time waiting.
When we boarded, we were full. It was a little tight in the middle isle. But pushback, taxi, and launch! NO delays at all, and I was expecting at least a few minutes in line for a runway.
The food was excellent. We had steak. The coffee was excellent on the way to England but lousy on the way back. Makes sense as the suppliers in England probably had terrible coffee like we found everywhere we had it over there. The hot tea was excellent, however. There was also this stuff called clotted cream....Mmmmmm!
My flight back was even more comfortable as we got the emergency exit seats (lots of leg room). So I had a great time with United.
Your situation, while aggravating, was infinitely better than having a four hour delay in the air, no? Safety first, and economy as well. Like the above poster mentioned about all the planes circling ORD waiting for the weather, they now have them sit on the ground burning less fuel.
Also, there is so much traffic, sometimes if a destination airport is swamped, an aircraft is delayed at the departure airport. Safer, more economical.
Could have been weather in the mix as well. ONE airport having weather delays can screw up the whole country.