Because both parents are now forced to work to pay the bills. Back in the 50s before women's lib, a family could live comfortably on the father's income. My dad was an underachiever so my mother worked as a secretary. But most of my friends had stay at home moms.
I think the suffragette movement was funded by the Rockefeller crime family as well. A majority of women weren't interested in politics and had no desire to vote. They figured since the man was out working and earning money, he was most qualified to choose politicians that served his interests. Suffragettes were mostly unmarried women who wanted to compete with men.