Yes, the system is a little bit broken. A "C" often reflects a "critical violation," something that went wrong, often can be promptly remedied, but under the system requires the face-slap of a week-long "A of Shame" before the inspector comes back for a re-do.
Frankly, a "B" worries me a little more because it hints at a regular pattern of letting things slide.
Of course there is also the hypothesis that a "C" may result from failure to notice an inspector's extended palm, but surely that would never happen in
our metro!