Probably because now that we aren't witnesses anymore, we can balance fun with seriousness. I enjoy both kinds of threads. There are usually enough of both. I'd find JWN boring if everyone had to be all serious all the time like well, a bunch of Jehovah's Witnesses.
Most of the truly serious thread makers left JWN a while ago. I miss them. They were the anchor of this site. For newcomers, I guess you just have to go back and get to know them through the old posts and threads. I miss Hillary Step.