I would not be surprised if some of the in-fighting between the various "specialists" on these fora leads to people giving up.
Also not rarely when newcomers first post is a question, invariably there will be a die-hard who points them to the search engine with little or no compassion. ouch.....
This hard direct hit attitude may scare off the newcomers.
Especially on the Private Flying I have no doubt the economic recession must be biting..... less student pilots = less PPRUNE readers?
I for one am still waiting for IO (is that a Walt Disney character??) to start a blog on GA.... I'll subscribe because he s hard hitting opinionated and knowledgeable at the same time, much better than the "let's protect the advertiser" traditional mags.