Tim Keller - why is the church full of moralists?

Jesus' teaching consistently attracted the irreligious while offending the Bible-believing, religious people of his day. However, in the main, our churches today do not have this effect. The kind of outsider Jesus attracted are not attracted to contemporary churches, even our most avant-garde ones. We tend to draw conservative, buttoned-down, moralistic people. The licentious and liberated or the broken and marginal avoid church. That can mean only one thing. If the preaching of our ministers and the practice of our parishioners do not have the same effect on people that Jesus had, then we must not be declaring the same message that Jesus did. If our churches aren't appealing to younger brothers, they must be more full of elder brothers than we'd like to think.
Tim Keller, The Prodigal God, p.16