I feel sometimes people just want to follow the trend, and at the present time in the UK it isn't seen as 'cool' to be religious. I know this doesn't account for all non-religious folk and that others are sticking to their own beliefs rather than being influenced by trends and the media.
It isn't about being "cool". The younger people haven't become part of the church because it's unfriendly and unwelcoming.
The church has lost its way. They have clung unflinchingly to out dated beliefs and values and pushed people away rather than brought them into the flock.
The church of my youth was a vital part of the community. Families met and gathered together to celebrate their faith and help those in the community who needed it. The church was diverse and was a huge family.
Over time the church has slowly become more and more insular. The congregation has morphed into something that many find distasteful. The church, in essence, has become more about itself, than faith.
Even as a young adult, when family needed it, we turned to the church.
As an adult, when my own family came to the church they were shunned and pushed away because of who we were.
Do not look to those without faith, or those that don't worship the church. Look within and see how you can change it.