I feel this is a facile interpretation of the phrase, kind of like complaining that "Measure Twice Cut Once" would lead to selling illegally adulterated flour. A more steel-man interpretation of POSIWID--the way I think it's intended to be understood--would be:

"The practical outcomes of a system over the long-term reveal something important of the the true-preferences of the various interests which control that system, and these interests may be very different from the system's stated goals."