I think I understand why you feel that way...after all, the dissolution of marriage has become a MUCH bigger negotiation process than deciding to get married initially...but I still must disagree, when children are involved. If we were to, in all cases, divide property between two adults in a 50/50 way, consider what that might do to the financial security of children who most often end up living in one household or the other. And also, to be fair, if we are going to say "oh well, you knew what was coming. 50/50, that's the deal", then how can we honestly then demand one parent pay yet another portion of his or her 50% to the other parent with custody of the child? You see, it can't turn out to be 50/50, not when children are involved. Someone is still, more often than not, going to end up paying more. And even if it COULD, even if the custodial parent didn't want additional support for the child/children, then still that child's/those children's financial stability has been reduced by half. For most people (not the mega rich), this type of division wouldn't be beneficial to children, who are also parties involved in the marriage.
People with no children, or adult children? Okay, I can see applying the 50/50 idea. After all, one can transfer part of one's wealth to adult children BEFORE remarrying if one wants. But when minor children are involved? I'm sorry, I just cannot agree with an outright 50/50 split. While it might not affect the financial stability of children of the mega wealthy,for average people with average incomes, it seems like an unfair thing to do to the children involved.