I think the point was that in an ideal world it wouln't be 'for just a few weeks' but would be for a more sensible six months, but few people can afford to take that much time. Most people work, because they rely on both incomes.
Having a new baby is exhausting. It takes more than a few weeks to not only recover from the pregnancy and labour, but the energy it takes to care for a newborn is indescribable. It is a blow, and to expect a person to go back to work right away in order to make ends meet is frankly expecting too much.
Yes, people give money, but no where near what it takes to pay the ordinary bills on top of what it costs to bring a new baby home.