>>We may find out things we don’t want to know,<<
That is probably what scares the senior officials the most.
You could very well be right...although, I work with classified documents and there are times when the bin is overflowing for perfectly valid reasons.
My boss, for example, is a pack rat and never gets around to shredding anything. The group admin assistant finally went in and, with guidance, filled three burn bags with very old documents.