There is something about cooking for someone. There is something about having someone cook for you. I would almost call it magical.
It's not purely about the taste of home-cooked food, or the admirable effort and thought that goes into home-cooked food, or that home-cooked food is healthier (maybe) and cheaper than pre-made food...
Cooking warms the heart because it is such a tangible way of showing people that you enjoy taking care of them. Not just that you can take care of them and will do it, but that you actually enjoy it too.