Just as one small example, daycares/schools will call for you to pickup your kid -- blowing up your day -- at the slightest indication of illness. With four kids going to school, this means two to six+ times a month your day is going to be completely blown up at any moment. I'm not complaining (though when I was a kid if you had a bit of a stomach ache you chilled in the nurse's office for a bit and 9 times out of 10 go back to class), but the average person cannot accommodate this without quickly finding themselves unemployed. This is just one of a million cases where two working parents and few or no supports leave you in a precarious situation.