My own response to Jason would be yes and no.
On the one hand, yes, I agree that the moral failures of the church, particularly over pedophilia, are sadly a significant factor in Christianity's western decline. It's difficult for the Christian movement to have any ethical credibility when significant authorities figures in the major churches have been found to have been complicit in the protection of pedophiles. It illicits disgust, and as any marriage counselor would tell us, that's a recipe for divorce.
But the other hand, no, I disagree that the shift from entertainment back to essentials is misguided. Any movement that forgets it's raison d'être risks destruction by centrifugal forces. That being said, I suspect Jason's understanding of the essentials and mine may differ in important respects. I see Christ-like love for the alienated as an essential practice and I doubt Jason would object to that if he realised that is what, at least some of us, mean by a return to the essentials.
Beyond all this though, IMO some of the exodus from Christianity has nothing to do with moral failure or misguided method, but everything to do with citizens exercising freedom. Some people reject Christianity, not because they've misunderstood it or been innoculated by lesser versions but precisely because they have understood it, authentically versions of it, and realised it's not the path for them. Where that is the case, should we not respect, even welcome, their decision to act honestly? Could it even be disrespectful at that point to assume, "Oh, they just haven't understood it!"
In responding to Christianity's western decline I think we have to recognize the limitations of apologetics. Apologetics is a discipline aimed at demolishing barriers to faith and building bridges to understanding. But as the old saying goes, you can lead a horse to water but you can't make him drink. Apologetics, even the best apologetics, can't compel acceptance, it can only extend an invitation. I therefore think we need to reassess our missional goals in the wake of Christendom, and pay more attention to the faithfulness of our witness and the graciousness of our actions than the strength of our numbers.