I think when my mother (and her mother) left the workforce to raise kids, it was a different scenario.

Their days weren't spent at home watching infomercials and watching the clock waiting for their husband to return. Their mother lived a few streets away, their sister would pop over for tea, they would spend some time at the neighbor's house...

Times have changed, and society has changed with it. In the country I am from, expecting your partner to fill in her days without working would be tough, and most women want to get more out of life. But as others have said, the only person who should be making this choice is the mother herself.