Actually this was a big feature of the new PC intonation that appeared in the late 80s and early 90s. Undergrads started saying declarative sentences with interrogative intonation-- as if they were actually questions. This allowed one to disclaim some responsibility for whatever one was saying, and yet at the same time to compel a response from the other person.
This way of speaking has now passed down to high school students and isn't associated with any specific sort of ideas (unless you count the empty set as a type of idea), but it was originally quite a nasty piece of conversational jiujitsu.
Rhetorical questions are still phrased as questions. It was "declarative sentence structure married to a question mark" that I was joking about. HN didn't think it was funny, clearly. :)
Imagine how a posh, and possibly a bit poncey Englishman might say "who", and you should be close to the sound of the U's in "jujutsu". The first U is elongated, and the rest are short.
This way of speaking has now passed down to high school students and isn't associated with any specific sort of ideas (unless you count the empty set as a type of idea), but it was originally quite a nasty piece of conversational jiujitsu.