Actually most forums are quite dead months after launch. You get much greater post volume for multiplayer games obviously because its in the games' nature to promote social behavior.
Or anti-social behavior, as is more often the case. I gave up MMOs because of community negativity. Playing single-player games doesn't make me hate my fellow humans like MMOs tend to do.
I prefer 'slower' forums like these to forums that are full of a lot of noise, where substantive posts are driven off the main page within minutes, if not seconds. Also Larian folks seem more apt to join in the conversations, probably because unlike other forums they don't get flamed every time they post.