In GNU, we appreciate humor in our work.
GNU is a project of hackers, and hacking means playful cleverness. Even the name “GNU” is an example of playful cleverness—it is a recursive acronym for “GNU’s Not Unix.”
In that spirit, we prize occasional doses of humor in GNU packages. Humor is not mandatory in a GNU package; we do not tell maintainers, “Make users smile, or else!” But when maintainers do that, we too smile.
Nowadays, our humor-positive approach occasionally encounters direct, blanket opposition. Some people advocate, and even demand, removal of jokes from software packages simply because they are jokes. We shrug off that point of view.
Jokes are subject to the same sorts of issues and criticism as other writing. Sometimes there is a valid objection to text which is humorous, so we do not defend every joke obtusely to the bitter end. But the fact that it is a joke is not a valid objection.
There are people who frown on anything that is slightly risqué or controversial, including jokes. It would be a terrible shame for that attitude to prevail, so our policy is that the occasional risqué joke is ok. GNU is a 21st century project, not a 19th.