Because I personally don’t want to pay $20,000 for my child to learn to make cheesecake. For that, I can keep her home and teach her myself.
I think what is more practical is to give the girls apartments and have them be responsible for their meals. Give them a weekly apartment budget at the grocery store (so they learn to compromise on what they can afford) and have each girl responsible for a dinner. Then mentor the girl on simple, good food.
It would take a lot less time and give them real understanding of cooking for a family. No formal lesson really needed on how to roast a chicken.