Not really, I've gotten used to not getting comments. As for why having a sketchbook and not keeping it open, it's for what I personally think a Sketchbook should be kept for, following your own progress (and getting constructive feedback, which is unfortunately rare). It's the CA.org mood that makes a Sketchbook different from my other art places as it always reminds me "gotta improve".
And I do mostly keep it open, it's closed only when I'm personally angry of my own work, so eventually I'll open it again, and close it, and open it and so on.
Fair enough. Doesn't it get lonely though? If you don't allow comments on your work, what's the use in maintaining a sketchbook? (not an attack, just curious)
It's locked because nobody gave me any real critique (okay, except maybe couple rare people).
Why is your sketchbook locked? I wanted to comment on your great designs, but I guess I'm not allowed to?