In our culture, lineage is passed down from the father. That's why most families definitely want to have a son. They also leave a large portion of their inheritance to the son.
Girls are usually more devoted to their families. I don't know if families are that fond of their daughters.
That is awful and outdated. It suggests the girl has no worth, except to slave for the family. That makes me very sad.
But why does it have to go on this way?
They want their inheritance to be in the hands of someone reliable, so that their lineage can continue and grow even further.
Is the assumption that women aren't reliable? In my experience, it generally goes the other way :D