Moderators on planebusiness are generally very passive; I've seen several flame wars on there go on for quite a while before they step in. (See one thread about homosexuality that dragged on and on and on....)
In addition planebusiness gets nowhere near the amount of traffic Flyertalk gets.. two completely different animals IMHO.
The only moderation I could understand is if the Flyertalk staff (ie those employed by WebFlyer) wanted to do it. Community moderation doesn't work and especially won't work in Flyertalk where opinion's keep getting in the way...
Besides, I think only the General Traveltalk, Omni, Buzz and United bboards are out of control... The first three is to be expected due to their nature; the last one is to be expected due to the strong emotions United elicits from its audience

I do think most air/car/hotel specific boards are relatively noise free and like it that way.
My $.03 (inflation)