They realize the majority of their beliefs already existed before they were born and will continue on after they're dead. They have nothing to add to the conversation while they are too busy fighting. They turn their focus to developing their ideas peacefully and let their subcultures flourish once again.
This isn't the first cycle and won't be the last. The last major cycle was in the 20th century due to broadcast media. I think people sometimes forget how relatively young the internet is.