I must say that I have never understood the purpose of having a human being enter a code every 108 minutes. Seems like you could just have a computer program that wakes up every 108 minutes and executes the necessary procedure.
Be that as it may, I do get the point of telling the people inside the Hatch that their job is important to prevent another Incident. But remember that Dharma had its own inner Circle of Trust, so probably very few people knew that danger was a constant possibility. So I get the purpose of telling the watchers in The Pearl that it's a fake experiment -- who would stay on the Island if you knew that danger was real? -- just to have an extra set of eyes checking that the button was always being pushed.
