Why does the Quran equate women with children?

One way to approach this would be to understand that the Muslim religion developed as a tribal law. In tribal times (and in tribes that still exist today), women were/are traded for a dowry such as cows/camels/money. This makes a woman the property of the man that bought her. His reputation within the tribe depends on his ability to provide for and protect his family. The basis of the husband being able to discipline his wife comes from a distortion of those basic tribal rules. Obviously a man can't be around to always and continuously protect his family (i.e. if they go shopping and she gets raped). So rules were made such as that she had to be with a man at all times when allowed out of the house, or that she must obey her husband because it is in the best interests of the family in terms of reputation and safety. That's also where the illogical distortion came where it's the woman's fault if she gets raped because she must have disobeyed the rules or something. Ignorance and a fierce desire not to change their primitive laws because the law is tied up with religion, is how this tribal law has survived in a world that we all claim is civilized.