I think it's because usually the punchline is too long
He thought it would help him with his hit detection.
You might think it's R, but his first love has always been the C.
A nun with a javelin in her throat. (The only joke I can ever recall when asked for one. Told to me by my art teacher in Grade 11. Needless to say, he was my favourite teacher)
Because their jokes weren't very funny.
The punchlines were too long.
Do you know the problem with UDP jokes?
The punchline is too long.