If C3PO is a protocol droid, why is he so annoying?

Question

Anybody who's worked in the US foreign service can tell you that people in charge of protocol are often very polite, very considerate, and very attentive to how their actions and words come across to others. It pays not to annoy diplomats and government officers if you have to work with them day after day, and ask them to do favors for you when interacting with their governments. And most importantly, a protocol officer knows what secrets not to say.

I would never hire somebody like C3PO to be in charge of protocol or even translations. He annoys people. He makes rude comments to Chewbacca, R2D2, and other protocol droids. He whines and complains and blurts out inappropriate statements. He's the kind of blabbermouth who would tell all your family secrets to a Sith Lord or a Hutt gangster. And according to an answer for this question, he was built from scavenged parts on Tatooine.

If all the other protocol droids in the galaxy are as rude as him, no wonder the galaxy is going to war! Everyone's droids would have ruffled the feathers (tentacles, eyestalks, whatever) of half the diplomats in the galaxy. Or maybe he's the only rude droid around because he's a custom made one-off built by a small slave boy to do housework for the slave's mother.

Is there any G-canon evidence of other droids being rude or annoying?

Answer 1

Back in the 70s, I remember Lucas stating that he originally wanted C3PO to be a "slimey slick-o used car dealer type" but once Anthony Daniels started talking he made the character into what we all know.

So, the character is there mainly for comic relief as Daniels himself stated:

What’s your favorite and least favorite line of C-3PO dialogue? My favorite line is — interesting you ask least favorite — my favorite line is, [in character as C-3PO] “We’re doomed.” It’s a phrase that encapsulates his whole philosophy. It’s his life. He always feels on the edge of disaster. That’s where the humor comes from because he is a humorous character, but mostly it comes by default. He doesn’t tell jokes. He’s just wrong about everything most of the time and lives on this precipice of fear, which gives a sort of tension. You and I hide that. You hid magnificently that you were terrified of talking to me. As humans, adults, we sort of do. He doesn’t have that guile. And in fact, now that I come to think of it, he is pretty much without guile. He says it as it is and that can occasionally be quite funny because he can be inappropriate without meaning to be. This is the thing that George and the writers originally created and we’ve taken it further and further. There’s no way I can think of the situations he’s put into, but they sometimes let me tweak [his lines]. In fact, they always let me tweak the script.

Plus: He also knows over 6 billion languages so I think of C-3PO more as an interpreter than a diplomat

And to answer your other question, yes there have been other rude droids:

• the other protocol droid in Cloud City was rude to C-3PO
• R2-D2 was rude to the droids on the Jawa Sand Crawler
• And there were other droids on the Sand Crawler torturing droids and restraining them