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.
It's locked because nobody gave me any real critique (okay, except maybe couple rare people).
Sometimes a wolf sometimes a bear, always a child!