Since men make more than women generally, if the nth percentile earning woman marries the nth percentile earning man, then the man will make more money, yes. That also means that if they divorce, the woman may take out more dollars than she put in. In the less common scenario where then woman makes more, though, she will take out fewer dollars and may have to pay spousal support going forward.
Meanwhile, custody of children in most jurisdictions is in fact gender neutral, and based on the best interests of the child. However, since more often the mother is the primary caregiver (whether stay-at-home or working full time), courts more often grant custody to the mother.
The first problem would be solved by eliminating gender wage disparities. The second problem would be solved by men providing more of the childcare during the marriage.
Ironically both problems have the same cause. Women do more of the child rearing and household chores. The wage gap is actually mostly a motherhood gap, if you look at the statistics.
I think you'd be hard pressed to find 1 in 10 divorces that "benefit" the man more than the woman. Just my intuition, I don't have any statistics on that. I have a really hard time calling that gender neutral.
I'd say the laws themselves are neutral, but situations vary. Also, 50/50 is just the default split; nothing prevents a couple from agreeing on a different split in a prenuptial agreement, which would then carry the force of law.
Divorce law is not gender neutral. Custody of kids favors the mother, does it not?
A 50/50 asset split disadvantages men on average because they typically bring more than 50/50 into the marriage.