It is interesting to note that looking at the Forum History there is a bit less forum activity these past few months although there's definitely a notable amount of page views. However I think there's been many interesting topics on Gallery, Modification, and General Discussion with intuitive or fun builds/mods and servers, albeit I think it is fair to say there's been less clan activity as of late, and I think the influx of people buying the game has been higher than ever. I'm also noticing there are more returning players which is cool, like Lordy Lord hasn't hosted a lot until Summer hit.
Fall is just a slower season than the others if you check out the trends in the Forum History - although not exactly representative of in-game activity, I wouldn't know as much because I log into Blockland probably once or thrice every month - but come Winter or Summer there'll be more people back playing I think, so all in all Blockland isn't out of commission just yet! I really don't think people should be phrasing "Why are there less people playing recently?" as "Is Blockland Dying?" because when I think of a game dying I think uh-oh Badspot fell into a pool of lava no one can pay for servers everyone is bailing their cars!