Because it wasn't the word of God. It was written by a Deuteronomist (book of Deuteronomy) who noticed that King Solomon was not taking life seriously (he was partying it up and living his life with few values) so the Deuteronomist wrote a bunch of laws (popular 'Jewish' laws at the time) and said they were the word of God so that King Solomon would see that he needs to get his shit together or else he's going to hell. It also was for the people as they went downhill in their principles just like their King. So basically those laws about gays going to hell and stuff were not true. The only word of God is the Commandments and even Jesus said that the one thing that matters the most is "love thy neighbor as you love yourself" which pretty much just means lvie a life with good values. Traditionalists pick and choose the old laws because they aren't fans of change in society. Clearly.