Why? Our standards don't change, a wrong's a wrong, even if you hate how it stays the same for us. And why a severe punishment? To deter others from following the same path.
In your society on the other hand your standards flip back and forth. Rapists are let to rape again, in our society a rapist would be put to death.
Divorce is at an all time high, adultery and promiscuity is totally normal.
Homosexuality is not only endorsed, it is admired and celebrated.
Beastiality although still unacceptable, it is practised in western sub culture and from time to time will make it on jerry springer like shows lol.
Government and corporate thieves run with millions and get a slap on the wrist while if they were in an islamic state, theyd lose their arm and think twice before ripping off millions from any individual or people.
For us, these things are timelessly wrong if they are and that's it. Social corruption is unacceptable.
And your lying about rape. The deck is tacked against women.
Under Islamic law, rape can only be proven if the rapist confesses or if there are four male witnesses. Women who allege rape without the benefit of the act having been witnessed by four men who subsequently develop a conscience are actually confessing to having sex. If they or the accused happens to be married, then it is considered to be adultery.
The Qur'an:
Qur'an (2:282) - Establishes that a woman's testimony is worth only half that of a man's in court (there is no "he said/she said" gridlock in Islam).
Qur'an (24:4) - "And those who accuse free women then do not bring four witnesses (to adultery), flog them..." Strictly speaking, this verse addresses adultery (revealed at the very time that Muhammad's favorite wife was being accused of adultery on the basis of only three witnesses coincidentally enough). However it is a part of the theological underpinning of the Sharia rule on rape, since if there are not four male witnesses, the rape "did not occur".
Qur'an (24:13) - "Why did they not bring four witnesses of it? But as they have not brought witnesses they are liars before Allah."
Qur'an (2:223) - "Your wives are as a tilth unto you; so approach your tilth when or how ye will..." There is no such thing as rape in marriage, as a man is permitted unrestricted sexual access to his wives.
From the Hadith:
Bukhari (5:59:462) - The background for the Qur'anic requirement of four witnesses to adultery. Muhammad's favorite wife, Aisha, was accused of cheating [on her polygamous husband]. Three witnesses corroborated the event, but Muhammad apparently did not want to believe it, and so established the arbitrary rule that four witnesses are required.