I will like to summarize almost all the points discussed so far and will add my own points in it.
First Question:
Why polygyny is allowed?
Ans:
It is allowed by Allah. The simplest answer, but we like to find reason behind everything. No one is going to stay with this simple explanation but at the same time no one has seen the day of judgment but they believe in it because Allah has told us through Quran and Holy Prophet (P.B.U.H).
So, let's try to find the logical explanations that our mind likes to hear.
1. Medically women are stronger than men. Birth rate of male is greater than female. Just checked it from Google but at the age of 65 the population of women is greater than men. In addition this sex ratio is greater at birth now days because of the selective abortion. In china the largest country population wise, only one child is allowed and people like to have a male offspring. This method of abortion is now widely prevailing in almost all countries. In case of wars, majority of the people dying is male. So, the countries that have gone through war or going through it lag behind in this ratio. So, there should be some legal way to deal with this imbalance otherwise you all know what will happen.
2. If a man marries more than one woman then the father of the offspring can easily be identified but conversely it’s not true.
Question 2
Why a man has an upper hand over a woman?
Ans:
1. There is not equal right for every one in every situation. For example a non Muslim can't be the ruler of a Muslim state. Then where is the equality of all human beings in this case. So, there are conditions for everything as prescribed in Quran. If a man has upper hand in this world then a woman has upper hand in the world hereafter. My question is , why she has an upper hand in the world hereafter and why she has 2-3 times more right on children then men. Why jannah is under the feet of women and not under the feet of men. There are certain things where women have superiority over men. So, in my opinion this question is not valid and you can't achieve equality in each and every thing.
Question 3
Why woman is given half share in property in comparison of the man?
Ans:
1. A woman not only gets share in property from his parents but also gets share in the property of her husband.
2. A person who marries a woman has the obligation to look after her. So, she is not responsible for the upbringing of the children and taking care of his partner financially.
It makes sense for a greater share to male depending upon his responsibilities.