When we go to some body's house, we should be polite and appreciate the efforts of hosts in treating us. They don't know about our tastes , likings and dislikings. So they prepare the dishes as per their recipe and they will feed us. Whether it is as per your taste or not,if you say food is good, they will feel happy. So a decent guest should talk negatively about the food they served. That is good manners. Some people without understanding these minimum courtisies they criticise the food which may hurt the host. Be good to them . Always appreciate their efforts in taking care of you. Never talk any negative aspects about them or about their treatment with anybody.