Parents vs In-laws

Today a French girl who has Indian roots asked me:
“Why do Indian couples have so much distinction between the girl’s and the guy’s parents?”

I tried to bullshit my way through by giving her the historical reasons about this tradition etc. but she persisted and asked me:
“It is the responsibility of the sons to ensure that their parents are well taken care of, even if it means that he moves in with them. However if the girl and her husband show the same concern for her parents then the society will make fun of the groom and brand him as ghar jamai or househusband and make fun of his manhood.”
Next she asked me why as an educated open minded person I feel that such practices are acceptable? I had no answer and I am hoping that my readers would help me find some.