That's what NWN was intended to be, a game for player made campaigns.
I'm not sure if that's a viable excuse for the OC to be of the quality inferior to that of some player-made modules.
Besides, you know how the NWN OC was advertised at first? It promised the singleplayer experience of BG2, alongside the DM client. To be sure, advertisements often exaggerate, but sometimes, things can get stretched just a
little far.
