Believe me, I understand the popular frustration with many Christians who are judgmental in a self-righteous manner.
Having said that, the Biblically correct position is to be (1) a stickler for God’s rules and (2) acknowledge that oneself can’t meet that impossibly high standard, either.
In other words, when a Christian warns the world, “Hey guys! These practices are all sinful! God is not happy about this!” the purpose should be to say, “That’s why we all need a Savior.” It’s not to say, “Man, I’m so glad I’m better than you heathens.”
In contrast, by watering down the rules to make them “reasonable”–things like, “Just don’t murder people or rob banks, and call your parents once a month”–then that’s actually attainable. So most people walk around thinking they’re basically OK, and it offends them to hear someone suggest God had to send His Son to die for their sins.
So to repeat: Correct Christian doctrine does indeed condemn the natural world as man has fashioned it, but that doesn’t mean Christians should feel smug. On the contrary, the sins they see surrounded them are just mirrors of how they were/(are?) without unmerited grace from God.
This also ties in to another of the huge problems people have with Christianity: “Wait, you mean some serial killer nutjob can just accept Jesus and then poof it’s all good? That’s crazy!”