In some ways I would guess it is a reflection of an anything-goes culture. However, it happens in the strictest of Christian homes as well.
The whole conscience thing is difficult to understand. I understand that it is sinful to violate the conscience (Romans 14) even when the conscience is not biblically trained. That is why I so often tell parents not to sweat the small stuff. When we have a large number of "house rules" that we cannot possibly enforce, kids can learn that rules are not that big of a deal. Kids tend to get in bigger trouble for violating Dad's kingdom standards than God's. So they learn to violate their conscience in bigger and bigger ways.
The cults, for instance, have long been very good at communicating their system of performance-based righteousness to their children. Consequently you see people two or three generations removed from the devout ones who still hold some of the accepted convictions even though they are no longer identified with the cult. That is why you have non-Mormons avoiding coffee and Coke, non-JW's arguing against the Trinity and non-fundyBaptists voting Republican. Then you have some who have turned to the extremes of sin but are still afraid to listen to a doctrine other than the false one they grew up with.
I am increasingly seeing that the common error in all these cults (notice I included fundyBaptists) is their trashing or at best ignoring the cross. They clearly communicate a system of rules that can never change a sinner into something better. When the only way to get or keep a right relationship with God is to perform, you either play the hypocritical game or you turn away in despair. The only difference among those with unregenerate hearts is that some can convincingly play the game for a lifetime and some cannot.
So when I work with a man who is more afraid of smoking a cigarette than he is afraid of God's judgment on his anger or addiction to pornography I do not start by telling him about Spurgeon's smoking habits. I call him to see the attributes of God, to hate his own depravity, to love the cross, to hate performance-based righteousness and to love the diverse kingdom of people redeemed by blood.
I really like John Calvin’s statement about substitution: “When we behold the disfigurement of the Son of God, when we find ourselves appalled by his marred appearance, we need to reckon afresh that it is upon ourselves we gaze, for he stood in our place.”