Because the people demanding this are wildly, disproportionately aggressive, and the number one priority of basically everyone at those firms these days is to just keep their heads down and stay on the gravy train. Even the CEOs.

It doesn't help that it's all phrased in moral terms. Managers there don't get any sense of morality from their work so they're extremely vulnerable to being told that they have to do X to be a moral person. They don't know how to push back and say "actually, my behaviour is moral, your behaviour is immoral, unacceptable and you will now be fired for it". Also: firing is a decentralized process and means fighting HR.