Long story short, this is not in all cases. In some cases, women get more than men. But in other cases, where there is a son and a daughter, the son would definitely get more. If one tries to think about the wisdom that may be behind this, one will realize that the male in Islam is the one that has the financial burden upon his shoulders; in other words, a male has more economic responsibilities than women in Islam, including it being obligatory on him to provide for his wife and children. Therefore, since the man has more economic responsibilities than the woman, in certain cases, it would make perfect sense that he gets more inheritance money than the women.
And Allah knows best.