Are you suggesting that the PC can do nothing but hurl insults at people? If so, that sounds a bit........more than a bit one dimensional as a character. If the PC isn't so incredibly one dimensional, then he will in fact be able to do something. Lots of somethings. Like, engage in the conversation in many different non-insulting ways.
No, not suggesting that he must only insult. But since social interaction tends to be seen as being the responsibility of the "party face" or "party spokesperson", and that in many cases, CHA is a weak spot. That weak spot should come into play just as someone's crappy AC should come into play in combat.
I don't think we're generally disagreeing.....my point was more about how those things tend to play out and how many are citing them playing out here in this thread. "Hey Mongo, you shut up while we talk to this guy."
Also, I personally don't have a problem if Mongo decides to speak up and insults the NPC. And I know plenty of players, even ones of more socially minded characters, who wouldn't mind either. So I don't know if I agree that this is even a problem in the first place, as far as insulting a NPC.
It can be, sure. However, if the only way a player can become engaged in a social situation is through insults, the problem is with the player and not the social interaction. That's a player that will cause the party and other players a lot of grief in social situations, which is a significant pillar of the game.
It may be the player's fault, sure. At least partly. There are other contributing factors, too, such as the GM attempting to involve that PC or not, or the rules not really having a lot of heft in this area, especially for certain classes and so on. Fighters can start with Proficiency in Intimidate, but not with Persuasion, for instance. I mean, guess how that person is going to try to handle social interactions.
And note, I don't think that's a problem in and of itself.
I agree and said so above. I do just that. My NPCs talk to different members of the party. I don't care if the Paladin is the social character in the party, if the NPC is having an issue with arcane wizardry, he's talking to the book Wormish wizard and not the Paladin.
Yes, that's the kind of thing I have in mind. I'd go even further and simply have the NPC ask other PCs about things because that's generally how conversations work. Even in a situation like this where there may be protocols and etiquette to follow. Why wouldn't the NPC ever think "hmmm they've no doubt asked the bard to state their case because he's a smooth talker.....let me see what this sneering brute over here has to say"? I mean, the OP makes an appeal to what's realistic, but expects certain party members to keep their mouths shut for purely gamist reasons.
And to be clear, I don't even mind the gamist reasons....let other players shine, niche protection, and so on....in and of themselves. Personally, I think the fiction can almost always be made to match what we want it to. But if a preference for "realism" is cited, I'd kind of expect that preference to apply throughout the encounter, and not just to the outcome.