Hmm, I think there are some things to consider.
First, as players, many people spend more time in game than on forums discussing said game.
Second, people who create modules probably require more forum time, seeking advice from others with more experience.
Third, not all module makers are of the talkative persuasion.
As a recovering World of Warcrack addict, I never spent one day on the forums (only if servers were down). If you are a player of NWN, there are literally thousands of modules to keep you busy. Also, as has already been pointed out, there are many PW and Modding communities whose members probably never even venture to this site, and there is nothing you or I could do to lure them away from their comfort zones.
Many of the people who post here regularly have been playing this game in excess of a decade, and probably know each other quite well. If the atmosphere seems chummy, it is not surprising. BUT, the NWN community is very inclusive and friendly, and I hope people always feel welcome to post here. Truth to tell, the fact that EA even hosts these Legacy Forums warms my heart toward that commercial institution.
There are lurking entities here who do not post because it is not in their character. Some people just aren't forum posters. Fear not, though, there are people like me who do enough talking for ten.