My ex took my last name, because he had siblings with children and my family name would have died with me. It was a gift to my father that his* grandson would carry the family name forwards. And no, that wasn’t a red flag – we were married for 30 years.
There are lots of reasons for women to keep their maiden name. In the case of my wife, she had two good ones:
She didn’t want to become disassociated from her scientific publications.
She didn’t want to complicate or redo any immigration paperwork.
Also some names just sound better. And some names go better than others with some surnames
My wife just didn’t want to change hers, so I changed mine instead. No need for a particular reason.
My ex took my last name, because he had siblings with children and my family name would have died with me. It was a gift to my father that his* grandson would carry the family name forwards. And no, that wasn’t a red flag – we were married for 30 years.