Why has divorce laws not been rewritten for todays world?

I have recently witnessed several people go through divorce, and can't help but notice the unfairness of the legal system in the situation. It almost seems as if there is a way it is written in the book that must be followed, and regardless of arguments, or who did what, it will only follow that way. Most of the time this benefits the women. My uncle set up an entire life a long time ago with a lady, nice house, new car, ect, only to have her sleep around. He treated her well. She filed for divorce, and told the courts she wanted nothing. none of his money, just sign the paper and leave to be with her new man. The judge said this is not the way it works, he owes you this amount of money for the next 8 years whether ya'll like it or not. Thats one example, but most cases seem very similar, usually pointed toward screwing the man over. Now back in the old fashion days, when majority of women were housewives, this system might make sense. I woman could have no means of supporting herself, and the man could kick her to the curb, and she would be screwed. No work exp, no money, no skill, ect. It could be bad. Todays world is not the same, many women easily have jobs and abilities as most men. It stumps me as of to why the system still has not been adjusted. If somebody like lawyers or huge political people were benefiting from this, i could see why they would refuse to change it, but this is not the case. They are married men under the same divorce risks as anybody.