Rudeness is completely arbitrary and you have to figure it what exactly is rude by, basically, upsetting humans and avoiding whatever caused the upset in the future.

People who either can't or don't want to do that say they're "direct" or "honest" or "logical" but there's another word for it, begins with A

I haven't read the paper but it seems like it's saying rude prompts are better, so isn't it reasonable to assume that's what they meant? If we want to talk about directness, that's kind of a tangent right? I see directness as an entirely different dimension, you can be very direct and polite, you can be very rude and indirect (e.g. passive aggressive). Maybe they should do a follow-up study on how well AI responds based on level of directness.

That’s mostly a problem for obnoxious people, honestly.