What should we learn from it other than that nobody should ever be punished for anything?
Hard to see how you keep a society functional with that sort of system.
You're being hysterical.
In a Free country, people should only be punished for infringing on others' rights via force and fraud. All all else is arbitrary law, and ultimately the gateway to Tyranny.
In any event, as for Sodom & Gomorrah: after just now re-reading all the Biblical material relating to that incident, it's abundantly clear that the cities were not destroyed merely for practicing the sin of homosexuality.
Indeed, in Ezekiel 16:48-50, God compares Jerusalem to Sodom, saying "Sodom never did what you and your daughters have done." He explains that the sin of Sodom was that "She and her daughters were arrogant, overfed and unconcerned; they did not help the poor and needy. They were haughty and did detestable things before me."
So much for the "God destroyed them because they were fags" canard.
Vote Trump!