Why the married girl must stay with in-laws? why the husband forced her to takecare his parents?

Its upto her wish/her decision whether to stay with in-laws or not.Most of the problem starts here.Why can`t the husband realise that his wife came to live with him and not with his parents.From her childhood till marriage, she stayed in her house independently.But immediately after 1 day of marriage,how it will happen?why no one realise this and leave the son and his wife separately?