I'm inclined to believe that it wouldn't matter. Some players are used to the "smile and speak nicely while holding poison to the cup offered in friendship" method, while I have a feeling that the vast majority are more used to the "slap back when you get slapped" method.
Here's some suspicions I have about things that might have happened:
1. Anyone, noble or commoner, who insulted the king would probably see his headless body soon enough, or dangle a couple of feet in the air. Perhaps in the better outcomes, the noble would be exiled forever instead. The commoner would probably die like a dog no matter what. In any case, there probably was a whole laundry list of protocols to follow in the royal court, so even if you thought the king and every other noble in the court was a huge idiot, you hated their guts with a passion, desired them all to rot in forever in a pit of despair, recoil at the very thought of even laying eyes on their disgusting beings, you never said so, nor gave any indication that such were your thoughts, at least not directly. Well, maybe some courts were different, I suppose, though I can't imagine how such noble pride would allow them to speak like peasants would. Hm, many of us probably lack noble pride because we aren't nobles, and so the acting breaks down when under pressure, or we slip up occasionally anyway. Ah....
2. If a religion has enough influence, then a noble of no significant standing in that religion would not do well to insult or otherwise cross the elders. I have a hunch that a noble in medieval Europe would have his life and career ruined at the very least if he ever said anything bad about the Pope. Not so in BM. Sure, you can get cast out of the religion, but, big deal, right? Most religions can't or have no interest, in dealing with those brash upstarts. Most of the time, that's justified. After all, who cares about what pointless generic noble follower says? It does get a bit dumb when a priest keeps being a jerk in the religion though, as that would mean everyone who doesn't care for his opinion must ignore him.
3. You know those duels that Tom says aren't meant for sport? Well, they were meant for something. Back then, I have a feeling that duels of honor occurred over the slightest provocation. So if a noble starts talking too bluntly to you, challenge him to a duel. If he refuses, everyone else in the realm should be laughing at him, ostracizing him, basically cutting him off like some noob on 4chan who asks why there are so many typos. But no, that ain't happening. Even duels till surrender are usually brushed off or punishable by the realm. That has to do sometimes with the practical considerations, especially during war. But here's a thought: Be more subtle with your insults and provocations, and then there is no justification for a duel. If you want to spit stinky dung out of your mouth, then expect to pay for it.
But this all said, there are characters who can be like this. For one, adventurers are commoners, and they have none of the training in flowery euphemisms, nor any need to practice that, except perhaps to be more demure in front of nobles. Rogues are cut off from nobility for various reasons, and that can justify the lack of decorum due to the time spent outside the circle. Outlaws are outside the reach of the law, one of the things nobles probably held sacred, and so it would be something like a noble being noble only by blood, but otherwise a despised criminal. Savages who were born into nobility might qualify as well, but it takes one heck of a twisted and despicable noble family to even accept those as legitimate. Maybe we should also ostracize entire families? That sounds good to me if a player consistently creates characters that keep insulting people with no attempts at being subtle about it.
Now, I understand that English is not the first language for many players, and that it is hard to achieve such a feat in another language. But those cases are often quite obvious, and hopefully the player at least appears to be trying his best to affect the air of nobility. I am talking more about those who have no problems with English doing that. For example, I have definitely been on the wrong side of decorum as Garret, Iksandros, Ramuh, Samael (Who started as a commoner), and Zephyros. In those cases, I sometimes faced the outcomes that would have been expected, meaning banishment and other sorts of stuff, which is a good thing. Still, I would say, even to myself, that for the most part, avoid saying things too bluntly, and if I have nothing better to say than a really questionable "You're an idiot/whatever other term", then better not to say it. Hm, come to think of it, I only ever called people stupid as Garret while still in SA back in 2008. Ha, SA does bad things to people I guess.
