I do not like describing falsehood. Besides, it is wrong to do so where truth may be described. In the words of God: What is there, after truth, but misguidance? (10:32). However, to clarify the subject, I will say a few words about the pre-Islamic era, known as the Age of Jahiliyya.
Prophet Muhammad appeared at a time when people had lost their knowledge of the true religion and had reverted to worshipping idols of stones, earth, bread, and even cheese. As stated in the Qur'an: They were serving, apart from God, what hurts them not, neither profits them, and they say: "These are our intercessors with God" (10:18).
They were so degraded in thought and morals that, as reported by Abu Dharr al-Ghifari, they would cut their idols into pieces and eat them. The only excuse offered was that they were following in the steps of their forefathers: When it is said to them: "Follow what God has sent down" they say: "No. We follow that wherein we found our fathers" (2:170).
They also buried their daughters alive: When any of them is given the good tidings of a girl, his face is darkened and he chokes inwardly, as he hides himself from the people because of the evil of the good tidings that have been given to him, whether he shall preserve her in humiliation, or trample her into the dust (16:58–59).
Women were despised, not only in pre-Islamic Arabia but also in the Roman and Sassanid lands. The Qur'an openly declares that men will be questioned concerning this: When the female (infant) buried alive is questioned—for what crime was she killed? (81:8-9).
After Muhammad had declared his Prophethood, a Companion told him what he had done with his daughter:
O Messenger of God, I had a daughter. One day I told her mother to dress her, for I was taking her to her uncle. My poor wife knew what this meant, but could do nothing but obey and weep. She dressed the girl, who was very happy that she was going to see her uncle. I took her near a well, and told her to look down into it. While she was looking into the well, I kicked her into it. While she was rolling down, she was shouting: "Daddy, Daddy!"
As he was recounting this, the Prophet sobbed as if he had lost one of his nearest kinsfolk. 
Hearts had become hard. Every day a pit was dug in the desert for an innocent girl to be buried. Human beings were more brutal and cruel than hyenas. The powerful crushed the weak. Brutality was taken for humanity, cruelty received approval, the bloodthirsty were exalted, bloodshed was considered a virtue, and adultery and fornication were more common than legal marriage. The family structure had been destroyed.
This dark period was followed by Islam. In addition to eradicating all other evils, God declared in the Qur'an: Do not slay your children because of the fear of poverty: We provide for you and for them (6:151).