"Second, I'm not convinced that disagreement about sexuality morality is a primary cause of departures. If that were the case, the mainline Protestant churches would be booming, but they're not. Most of them jettisoned traditional Christian teaching on these matters a long time ago and still they languish."

This comment assumes that mainline Protestant churches began to see a decline in attendance AFTER they changed their tune on sexual issues, which happened rather recently, not "a long time ago." In fact, there's every reason to believe that their decline began well before that, when they were singing the same tune the Roman Church is now. It's quite convenient for the bishop to gloss over the dissatisfaction of disaffected Catholics and blame their "lack of faith" as the primary reason they've left the church - that absolves him and his fellow bishops from scaring people away with their teachings which the disaffected see as hypocritical at best and cruel and un-Christian at worst.