@jo_with_no_space, I don’t think it always does. Saying “your behavior has really upset me” should draw an apology if the person didn’t mean to upset you, and they are sorry that you are upset. That doesn’t mean that they are sorry for their actions. On the other hand, saying “your behavior has really upset me” could result in a response of “you have no reason to be upset” which could either mean that they person thinks you’re overreacting, or that you interpreted their actions wrong.
Saying “you owe me an apology for your behavior” usually results in “I’m sorry (is the conversation over now?)”
I’m married to a person that never, ever apologizes, and he’s done some pretty awful things. The net result of not paying attention to how your behavior could possibly impact those around you is that it builds walls and barriers, because the person leaves you with a sense of needed to protect yourself from them emotionally. However, apologies are just words, and the real apology is a behavior change. If the person says sorry and continues to act in the same manner, then they’re really not sorry that they upset you. They’re sorry that you’re not okay with what they’re doing.