In all seriousness, the App-Store guidelines on what can be approved or not are most likely written to vaguely that it is up to the reviewer to decide what they mean.
Reviewer #1 may be a liberal, and will pass the app without problem.
Reviewer #2 might be an evangelical x-tian and will deny the app.
Extrapolate that out to however many reviewers making those decisions, and you can see it is pure luck that gets some apps passed (Shake the Baby and Pee Monkey Toilet Trainer), while others get knocked back (Eucalyptus and the NIN app).
"But the guidelines Lord Jobs gave us say..."