It's pretty simple, it's a fantasy passport, not legitimate.
In amongst the article here is a very important statement. It is claimed that '... the South African government has previously accepted the World Passport to enter the country and to provide visas as recently as August ...' . In these other cases, it may be the case that a visa has been issued through ignorance, it is also possible that it has occurred as a result of a light-hearted placement of a legitimate arrival or departure stamp in the World Passport, even though the traveller entered the country on a legitimate travel document.
Requests for the placement of legitimate stamps in anything other than a legitimate travel document should be refused by all border control officers.