We don't have a place to sketchdump, though. If you're talking about the Gallery, it lacks integration, does not suit the purpose of sharing art with many people at once, can easily be disorganized and does not auto-update with new posts. That's why following an artist's progress, which is the purpose of a sketchdump, is a hassle and is not particularly community-friendly if we use the Gallery. It's definitely broken and needs some tweaking, in that respect.
Yes, we are an art community. But having your work stashed away in private means you are not effectively part of that community. Being part of it is about observing other peoples' work and vice versa. How many members do we have whose art does not get seen because they either don't post on the forums or post exclusively in the Gallery? If you click the Gallery tab, you will be presented with thousands of pieces of artwork, which is a hundred fold the volume of work presented in the actual CC. They use up bandwidth, without actually being part of anything we do as a community.
Besides, the nature of the current CC keeps most artists from dumping there. Honestly, if I had posted every sketch I'd made since I last updated, that thread would be well over 30 pages long, with very little to comment on. In other words, it would clutter up my thread with pieces that aren't, because of their loose and experimental nature, worth commenting on. And I often seen artists marking pieces like this in their CC threads -- "it's just a sketch, not really for critique" -- because they don't really have anywhere else to put them without hiding them away in their Gallery.
Evidence of this: Right now the closest thing we have to a sketchdump section is the "let's exercise" thread, which is kinda like a group sketchdump. The members who post there are far more prolific in that thread than they are even in their own art threads.