I think it comes down more to them not knowing exactly when the sausage is made. They can agree if the sausage is good or not when it comes out of the factory,

I think it comes down more to them not knowing exactly when the sausage is made. They can agree if the sausage is good or not when it comes out of the factory, but what happens in the middle is less clear. The thinking goes, "code gets output typically when this person sits at this desk, and so when I don't see them sitting at this desk, they probably aren't outputting code."