It’s only men that usually can’t figure out how to spend their nestegg; many women have no such problem. Yes, I know there are exceptions.
I think that it’s part of our God-given differences. Men are usually providers, women are usually nuturers. Women can find ways to make a home more “home-y” more than most men ever could. And Men can provide and protect more than most women ever could. Just as you said, there are exceptions, but I think by and large, men are used to bringing things/money in, so to speak, while women find ways to use it. I find nothing wrong with that, just two sides of one coin, united in marriage.