It’s because they don’t want to get the passengers off the plane. Doing that puts the flight into a different category.
I just woke up so I’m hazy on the details, but if the plane doesn’t return to the gate, then the flight is just delayed or something. If the passengers actually deplane, then it gets marked up differently in a way that the airline can be fined or otherwise held legally liable for something or other. Also, they have to do all that pre-flight maintenance stuff again.
So it’s about the money.
I’m surprised nobody opened the emergency door to force the issue.
