I completely agree, with one exception:
It’s not just UAL. They are just the ones that got caught.
You're right. I was just using UAL as the current example, but a couple of recent experiences on Southwest bolster your point. Last week I flew into PBI. Flight was considerably delayed due to weather. We got in line to board, and just as we were ready to start SW announced that PBI was closed to president Trump's landing on the airfield. Another hour delay. Then we took off arrived and were not allowed to deplane for 50 minutes because our gate was busy. Now this is near midnight at a Podunk airport where no other planes landed or took off during the entire time we were help prisoner on the tarmac. They couldn't find another gate? When we finally got off we noticed that there was an enormous plane with China Airlines written on it parked not far from the terminal. The gate wasn't in use so much as they didn't want us peasants mingling with the Chinese staffers who were traveling to Mar a Lago. They lied about the reason.
Last month my kid was on a flight to New Orleans (again Southwest) and rather than land they circled for nearly three hours. When they landed the noticed a eve of emergency vehicles waiting for them - multiple fire trucks etc. they then waited on the tarmac for another hour or so and went to the gate escorted y the fire trucks. Southwest said that the brakes overheated because they had to come in fast due to wind. This was very late at night, and couldn't they come in from a different direction or a different runway? I suspect they had a potential landing gear problem and lied about that. Why else burn off fuel PRIOR to landing? So yes all airlines are arrogant and lie about stuff all the time. UAL just happens to be the one in the spotlight this time.