IMHO there are two primary reasons for the decline in organized, mainstream religions: 1. Many Christian religions have embraced the influence of the PC crowd even to the extent that it is in conflict with scripture--this is a huge issue for people that look to the Bible for guidance and not to the arbitrary leaders of the PC church. 2. The constant assault by the old media and hollywood who view the church as a threat to their power to shape opinions and to compete with their financial gain. It is a control thing from the left, the secular worshipers, and mind controllers.
I would tend to agree with your assessment.