I like the following as a working definition of the problem we face as the church:
Church leaders seem unable to grasp this simple implication of the new world–people outside the church think church is for church people, not for them.
In other words, whatever it is that people are looking for, they are not looking for it from the institutionalised church. So, all the energy we pour into making the institution of church more attractive might just be an enormous waste of energy, and a resource better spent elsewhere. People don't necessarily want to be part of church, but they might be interested in a movement.
Fortunately, although Jesus did say he would build his church, I think he had something more in mind than a self-perpetuating institution and more like a mass movement of people experiencing the transforming power of the gospel.
That's my guess.