Further analysis might conceivably yield a useful insight - I'm only suggesting that the claim as it stands is an over-generalisation and has exceptions.

As well as automation programs, we must consider programs that are run to occupy time or burn resources, programs that are run in order to DOS-attack the computer (see The Forbin Project), pointless programs, and so on. In such cases the output may be irrelevant or non-existent, rather than unknown.