To be honest, I don't see anything wrong in your scenario. People fall out of love for lots of reasons, making them miserable by making it harder to split up doesn't seem like a particularly good solution to me. The scenario you've raised would have to involve a very emotionally shallow individual whom the other partner would be better off without anyway.
So you think half your future earnings is a reasonable price to pay to rid yourself of a shallow partner?
Is Shallow Hal doing the majority of the childcare? Do they need to find somewhere to live to perform that function?
In the general sense that a house husband should be treated like a stay at home mom in a divorce settlement, there is nothing at all wrong here.
Didn't you just write in another post above "There is only one acceptable level of violence and abuse and that is zero."?
Suppose you were a stay at home dad married to a high earning wife. You then meet a new woman you find more attractive. Under most Western countries' laws you can divorce your wife for no reason other than you no longer find her attractive, and she has to pay you alimony and child support to maintain your lifestyle while you're dating your new, hotter partner.
What's the downside to you? Seems there isn't any.
It seems obvious that a system setup like that will increase divorces initiated by stay at home parents, and hence increase single parent households.