Tim
What you need to understand is that all law in this land is based on a single tenant, to be fair, what you suggest is to take and end result and not why or how it occurred, this could never happen here, nor should it ever happen.
Both the marital causes act and the childrens act underpin the needs of children, why?, because they are innocents and vulnerable, i find it hard to belief any parent would disagree with this.
So we have a woman commits adultery, with your idea the court take the children and give them and all assets to dad, but what if dad works?, what if he can`t afford to stop working and be a stay at home dad, but far more importantly what do the kids want to happen?, of course kids want a mum and a dad, but if they have to live with mum or dad or share surely their thoughts and needs are paramount, if mum went astray and the court say well your now living with your dad but they want to live with mum your punishing the kids for what their mum did, how could that ever be right?.
In fault based law which is what you propose i know of no law which will accept the event without considering cause, 1000 years ago yes, if you were seized stealing a dear from the kings land you were hung, i would like to think we have evolved a little since then, today the fact that you were trying to feed your starving family would be a mitigating circumstance.
Think of it this way, the law says you cannot assault another person and courts have guidelines when sentencing.
A bloke punches another guy in the face breaking his nose, actual bodily harm, do you send him away for 18 months full stop?, or do you consider why he did it?, does he have a violent history? does he have a mental health issue?, what if the guy was walking home from work corners the road and finds a man beating a woman to the floor, the woman is hurt, he can`t pull this man from his frenzied attack, so he hits him breaking his nose, event and cause, be fair.
What is suggested is indeed very simple, but far too simple, and far from just in anyway, there are many problems in law, many do their damnedest to try and improve things which is commendable, but what is suggested can never happen nor will it, if it did i would move to a country with a more even approach, North Korea, China, Maybe Yemen.