Perhaps you now agree that the system is failing many individuals. There is no transparency with regards to the internal process- and in particular why certain applications should take months or years longer than others.
This is unlike PR files which are processed to a 6 month target- in fact they process quite a bit more information and checks for PR than for citizenship including medical, education and typically 10 years of background. Mine took 4 months.
It would seem that some kind of criteria are applied to citizenship files which makes them non standard and/or perhaps a certain percentage of files are selected for advanced review/quality control. This isn't a problem with PR- as it's processed to a 6 month standard, For all but the most complex cases.
So what's probably happening is that once marked as non standard/quality control/etc, it goes into a low priority queue, with months of delay before the file is picked up. When it is opened by an officer, either they process it, or kick it further down the road, depending on factors that are unknown to us (The only valid reason for a delay could be waiting for information from a third party, but this would be rare).