The act of imposing humility upon another person is called "humiliation"."
What I really want to point out here is this:
"having a clear perspective, and therefore respect, for one's place in context."
Pope Francis recently provided a wonderful example of this by responding, "Who am I to judge?" when asked about the status of gay priests. His humility ensured that his office didn't mean that his place in the world somehow changed him from just another sinner in God's eyes.
What it also meant at the same time was his affirmation of others' place in the world. He was saying to them, "Yes, you and I are both here, together and you have a place in this world, and it's the same place as mine." His response was a complete reversal from years of attempts to push people out of the church, to take away their place both in the world and in heaven.
Humiliation is an external pressure to try to enforce humility, so it is therefore cannot be humility which is internal. And any attempt to externally enforce humility cannot succeed, because there is no respect both towards oneself, or toward another.
If you have humility, you don't have to be afraid of humiliation, embarrassment. You don't have to be afraid of being found out as a worthless, incapable, bad person, because you have tried to clearly assess your own flaws, weaknesses, foibles, and you remain open to the process of learning more about them. No one can humiliate you when you have humility, because you know your place in the world, and the respect accorded to others extends to oneself.
Without humility, criticism can sound like condemnation and humiliation.
It's not always as simple and clear cut as saying, "I don't like this". Any kind of even implied criticism can feel like that. And if you are feeling condemned or humiliated, what happens? You start avoiding people and situations. And people start walking on eggshells around you and vice versa.
There are whole avenues of conversation and thought and feelings that must become off-limits in order to maintain a relationship with someone that could perceive almost anything as criticism, whether or not it was intended that way.
Without humility, apologies are perceived as capitulation to external force, rather than sincere attempts to repair and restore a relationship.
If I believe that being forced to apologize to another person means that I am acknowledging that I am a bad person and they have "beaten" me, imagine what that means when I am in a position to accept an apology?
I might feel that because they had to apologize, I am inherently a better person. They are the ones who were bad, and by comparison I am not as bad as them. It doesn't necessarily mean that I think I am a good or great person. But at least I am not as bad as them.
Or I might feel that by asking, or even seeming to hint, that I wanted an apology for something I would necessarily be causing them humiliation, so if I saw myself as a "kind-but-proud" person I would surely try to prevent anyone from feeling that they might need to apologize. I would just swallow all bad feelings caused from hurt, because if I had to apologize for something, I would feel humiliated. This logic gets all twisted up until you can't apologize or be apologized to - there are no longer any methods to repair and restore relationships. There can be no relief from pain, and no way to provide it for someone else either.