I hadn't seen that one :) Someone above mentions its VB6 with embedded SQL Server upgraded from COBOL [1]. Can sort of see how they don't want anyone looking at it now.
It seems to be an ongoing misconception in the public, that part of good security is obstification. Know of any simple clear articles I could point people to when they make these sort of ("because Hackers might see") claims?
Certainly reminds me of this xkcd: https://xkcd.com/463/ It sounds like security...