I have the perspective of a private practitioner, whereby we hear reports from the bureau on such things as these statistics. Ultimately, we're not in the decision-making room, where priorities are set.
The bureau has enforcement priorities, which they publish every year. From my observations, it seems that if you have a matter that falls outside one of those priority areas, it's more difficult to get the interest of the bureau.
I think ultimately it comes down to a question of resources. Of the 467 complaints, I doubt that all of them were worthy of carrying forward to the next level, but surely more were than the bureau was able to take a look at, with its budget limitations, given that other parts of its mandate, such as criminal enforcement and the mandatory merger review, face more fixed costs. When there's some squishiness and money has to be cut, my perception is that it is more on this type of stuff, the reviewable matters.