True, but this makes my point about why having skill bonuses inflate dramatically and DCs go up correspondingly is a problem. If the DC is set to challenge the face character with a massive bonus no matter what the barbarian does he notches a failure, unless the DM pushes the DCs around.
In 4e, this will only be a problem if the GM ignores the actual rules for DC by level. I'm sure there were plenty of GMs who did that - but that feeds into the discussion in another current thread about GMs who play systems that have clear and working encounter-building guidelines and ignore them. (I call those GMs
bad ones.)
The 30th level fighter in my 4e game has a CHA of 10 and no trained social skills, but is able to succeed on Diplomacy checks from time-to-time.
This is why many skill challenges were written the way they were. I understand what they were trying to do but often felt that, at least the way they were implemented in play (and I played with three or four different DMs, so it wasn't just one) they tried to force participation and often turned into a situation of "guess which skill applies here".
My view is that there is a significant gap between the actual rules and advice for skill challenges, and their presentation in published modules, much as there is a significant gap between the advice for encounter building and establishing quests and their presentation in published modules.
To some extent this was probably inevitable, in that 4e as presented and in its advice is the least GM-driven version of D&D published (at least since Moldvay Basic) whereas contemporary modules are all about a GM-driven play experience.
But anyway, the idea that a player needs to "guess the skill" is completely at odds with the DMG advice, which says (i) that players should explain what their PCs are doing to resolve the situation - which is fiction first, skill second (although the player's description of what his/her PC is doing may include reference to an intended skill), and (ii) that the GM should indicate what skills might be useful (in my own experience that's normally redundant because a vivid description of the fictional situation should make that clear - but in any event it speaks directly contrary to a "guess the skill" approach).
The social system works very differently than combat in most games. Combat does some damage and the wizard doesn't have to just sit there in melee but has various abilities to escape or do something. In the social system, most non-social characters essentially have no ability at all, certainly in higher levels.
If the player of the wizard doesn't want to solve the problem as a melee one, s/he declares appropriate actions to change the situation. (They may or may not work. They may or may not be popular with other members of the group.)
If the player of the barbarian doesn't want to solve the problem as a social one, s/he declares appropriate actions to change the situation. (In People of the Black Circle, Conan meets the princess (?? queen?) - a social situation - but then kidnaps her, changing the attempt to persuade the governor to spare his men into a different sort of challenge!)
If the convention at the table is that one doesn't do that, then the barbarian player either needs to build some social skill into his/her PC, or cope with the fact that s/he will suck a bit. In my 4e game, there are two CHA PCs with good social; a wizard/invoker and ranger/cleric who have unexciting CHA but social skill training and hence average social; and a fighter with 10 CHA and no social skills. The player of the fighter just sucks up the fact that often his attempts at persuasion will not succeed; and sometimes he looks for other ways to contribute
When the PCs were trying to persuade the Raven Queen's marut allies that the end times had not come, because this arising of the tarrasque was
not the one that signalled those end times, the fighter's contribution was to solo the tarrasque for a couple of rounds and come close to killing it single-handedly - which showed, as one of the other PCs explained to the maruts, that this could not
possibly be the coming of the tarrasque that was meant to herald the end of all things.
Social situations are only different from combat situations if the table chooses to make them so. In which case they can hardly complain about it!