It has noting to do with pressure i agree but also i think it is far deeper than just the manager,
Remember Blockbuster video rental? That is United now, living on a reputation and previous market share with no new ideas or innovations, competing against the Netflix, Prime, Disney's of this world. We are a middle table team way overarching, we try to buy our way out of trouble but the people making those decisions are not qualified or anyway near the level of our competitors. I have heard countless times that United is too big to fall, that is fallacy, there is countless companies that thought the same in the past.
Our only real hope has always been new owners as that is where real change begins no matter who it may be, until that day we will have to endure unfortunately.