Please think about what you are saying for a minute.
You are saying that if one of the parents sacrifices their future to care for the child, and the other does not, during a divorce, the latter does not owe the former anything.
The better question is - why do you want to moat the latter parent moated from the duty of parenting so much?
Or, if parenting is too complicated, here's a simple example.
Bill marries Jill. Bill works, buys their food, pays their rent, pays their bills, does the housework, and pays Jill's way through medical school. Bill and Jill have no assets, because all the money went into Jill's education.
Jill graduates, becomes a doctor, starts making mountains of money, meets a pretty intern, and divorces Bill.
Does Jill owe Bill anything?
It's the same situation as with childcare. Bill put more into maintaining the marriage/child than Jill did. Jill benefited/was harmed less during the marriage. Bill deserves compensation after the fact.
Had the fruits of his labours gone into a savings account, he'd receive at least half of it on divorce. Instead, they went into developing Jill's earnings potential - so he's entitled to a share of it. Likewise, if instead of paying with money, he paid with childcare that was damaging to his career.
That actually depends. Some states put a large weighting on lifestyle costs. So even if Jill is making tons of money, she probably won't be required to pay anything if she has been spending it on a BMW and other expensive things. Even if that were not the case, most states would not require alimony if Bill is still working. Also, some states would consider the education costs a gift and it would not entitle Bill to anything.
> Also, some states would consider the education costs a gift and it would not entitle Bill to anything.
Would they consider rent, food, utilities, and everything else a gift too?
A marriage is a not a quid-pro-quo financial transaction. It is an entanglement of two people's lives. The purpose of divorce court is to unentangle those lives in a fair and equitable manner.
One person supporting the household, while the other mooches off them, and then divorcing right when they start becoming responsible for supporting the household is not a clean break with zero financial entanglements.
Imagine if instead of pouring money into an education, Bill was supporting Jill as she was building a startup. He kept the family afloat, he poured money into it, while it was running at a loss - and then, right as it turns profitable, she leaves him with nothing.
Would that be fair and equitable? If not, why is a high-earning education any different? [1]
[1] The difference is obviously, that in this case, the startup's ownership would be split between the two spouses, with the spouse that financially supported the founder receiving a portion of it - probably not a 50/50 portion, but some portion nevertheless. An education's ownership can't be split... But the wages derived from an education can be.
I take issue with your statement on divorce being fair and equitable. Even if that is the stated purpose, it's rarely the outcome. In most instances I feel that fair and equitable are often opposing outcomes in a divorce. Is it fair to split the assets 50/50? Is that equitable? How do you even measure the equity for non-monetary contributions? Now, how do you account for whether or not the person would have needed to perform the same tasks outside of the marriage (cooking for themself vs cooking for two)? Most of the court's solutions for this are either based on inflexible formulas or on the emotions and bias of the judge.
Your statement about credit for paying all the utilities is not how it works. In fact, that can work against you. Like I stated before, lifestyle can be a big part of the decision. The spouse paying all the bills may still be required to pay many of them because the other person has a lifestyle the court wants to preserve. Take for example the divorce in California where a man had a porn addiction and the wife was ordered to pay alimony to continue supporting that addiction.
Your example of a startup is not the same. A startup is property, which can be sold and has inherent value. Being acquired during the marriage, that makes it marital property.
Coming back to your previous comment, do you really think that is a fair split at 50/50 even though one person provided the intellectual capital and work? That would be devastating to most people to have their "baby" of a company ripped from them to the point where they no longer have majority ownership.
They are a parent by their own actions, why should they be moated from the duty of parenting in the case of a divorce?