Why does mother-in-law look down on daughter-in-law?

1 gave birth to a daughter. Although young people nowadays pay less attention to having boys and girls, in the concept of the older generation, having a son can continue the family's incense and pay less attention to their daughters. This concept is not formed overnight, nor can it be changed overnight.

2. The mother-in-law is too strong. Some mothers-in-law are strong but sensible and reasonable; Some mothers-in-law are used to being strong all their lives, not only taking care of their husbands and sons, but also trying to control everything after having a daughter-in-law. As long as the daughter-in-law goes against her wishes a little, she thinks that the daughter-in-law is unfilial and naturally looks unhappy.