Is not husband having no right over wife's salary a bit injustice?

Suppose i am married with a earning wife. We both earn the same. I am only son of my parents and she is also only issue of her parents. Now as i have to look after her expenses and also my children i can hardly give 10% of my earnings to my parents. But my wife gives all her salary to her parents as she need not to give any money to run our family according to Islam. So i cant help my parents as much as she can. Isn't this a injustice to me or my parents? Why my parents will get lesser from me just because almighty gave them a son not a daughter?