I've never been one to post frequently in any message board community I've been a part of, but that's my personality. In face-to-face conversations, I'm fairly quiet, too.
But I think certain sections of this board, like Let's Talk Kindle! have become more cyclical. If a new product is being rumored, then there's a lot more speculation, then who all is ordering, then there's the reviews and troubleshooting when the new product is out. The thing is, Amazon has addressed a lot of the issues that were previously discussed on here, and given us Kindles for all types of situations: the Fire, the Touch, the old-school Keyboard, and the DX. We still don't have a non-backlit color screen, but that may or may not ever become a reality.
Also, the Kindle is no longer as new as it once was. Yes, there are still people who are new to Kindle but for many of us, we've gotten comfortable with the product and no longer have the same questions that we once did.
At some point, when the same conversations were getting recycled, I started to feel like my responses were a broken record. So, I personally avoided re-answering the same questions and let others (newer posters) answer after a while.