My mother always loved being a homemaker, but she understood that wasn’t every woman’s calling, and she worried that we all lost something when, over generations, women desiring a career were dissuaded by society’s traditions. Somewhere inside the mind of at least one of them, she reasoned, we might have lost something invaluable, like the cure to cancer. Imagine if Joan of Arc, Marie Curie or Afghanistan’s Malala Yousafzai hadn’t made their mark. Them, we know. Most women who broke with tradition have gone unheralded. When I started in television journalism in 1976, there were a few women reporting at...