Great post! I have always felt it's most healthy for married couples to share finances. It's best to consider finances as "our money," instead of "your money" or "their money." My wife and I have always shared - but we got married young (at 21), and it never occurred to us not to share.
I'm saying this as someone who has always made at least twice as much as my wife, since she was a teacher for 30 years until she retired. I always viewed us as a unit - "two becoming one flesh." However, neither of us has been "overly" foolish with money, and we had the same financial goals. If one of us had issues with foolishly spending money, we may have considered splitting finances - but we never ran into this.
My daughter recently got married at 27, a little later in life than we did. It took her and her husband about a year before they combined finances. They have an interesting dynamic in that she makes more than he does (she's an actuary, he's a chemical engineer), but he's better at saving than she is. She really likes to travel to see her friends all over the country. But they're working through it.
When I went through marriage counseling at our church 35 years ago, my pastor told me the two most important things to a marriage were finances and making my wife feel safe. I have always taken this to heart. There has never been "financial infidelity" in our marriage from either of us.