Because they never do anything wrong. This is the first rule any good relationship. The second rule is that in any dispute you must refer to rule 1. Women can never be wrong, belch or fart, if they couldn't (*)(*)(*)(*)(*), they would explode.
Women have no need to say they are sorry because men beat them to it. Any man who has spent time in a relationship with a woman knows full well that she MUST win every argument if he hopes to enjoy life. Should he win he will get 20 seconds of success followed by 2 to 5 days of suffering. The wise man simply says he is sorry and waits for make up sex.
This reminds me of a joke I once heard. We have all heard the saying "If a tree falls in the forest, does anybody hear" ? If a man is walking in the forest talking to himself..... Is he still wrong ?
The answer to this is very complex and based on multiple factors. If the man is indeed completely alone, as in no sprites, fairies, or wood nymphs he is not completely wrong per se. However, critical evidence (vindictive nature and multiple personalities), point to God being female which would indicate he is never truly alone. Thus is the man always wrong regardless of physical solitude.
Because if she doesn't, and you stay mad, another dick is waiting around the corner to go deep inside.
You might be dealing with the wrong women, mate. I've found that guys apologize less easily than women. The only thing, in personal experience, that I have noticed that's worth mentioning here is that women who do apologize are much more likely to do it facetiously. I've had a couple in particular apologize with an overtly sarcastic tone and then be surprised when their apology isn't taken at face value. But I also recognize that most women are petty like that. Move on, find another one. The pettiness just isn't worth your time.