more than a punch line

[ckok]

"...Germans care deeply about the privacy of everything...except their private parts. That's more than a punch line. Behind that observation lies a lesson and a question...:Why is the private private?..." (Public Parts, by Jeff Jarvis)
What does "to be more than a punch line mean? Thanks in advance

[Bennevis]

A punch line (or punchline) is the final part of a joke, comedy sketch, or profound statement, usually the word, sentence or exchange of sentences which is intended to be funny or to provoke laughter or thought from listeners.

It means that it's very funny but there is more to it.

[ckok]

Thank you