So I think personal ability really is dependent upon the game being played. Ones not so challenged, like most physical abilities, except perhaps a well flexed and oxygenated brain, are going to be left out of tabletop games. It's just one of those things. The mental traits in D&D I see as additions or subtractions to player abilities, but the players mental ability still matters - whether that be intelligence or wisdom or charisma or memory or creativity or what have you.
I think there is a reason why charisma is often the first ability that provokes this discussion. There are two separate things here, but in these discussions they often get conflated:
1. The player using his imagination, creativity, etc. to arrive at a good plan or what have you--then try to execute that plan with the character abilities.
2. The player falling back on his native raw ability to trump his character abilities.
Now, it is seldom that clear cut in practice (mainly because it would be so transparent). But visualize a player confronted with the need for the party to sneak into a hostile town. Assume his character isn't particularly strong in any mental stats, but isn't awful in all of them. It isn't unreasonable to suggest disguises, posing as pilgrims, merchants, etc. Or more risky, they waylay a messenger and take his place. Or any number of such things, depending upon their exact situation. Then the party tries it. Fine. There are some inherent advantages or disadvantages in the situation based on what they do. If they go the disguise route, and pick something that is common in the town, and easy to fake, then they get situational bonuses. These are appropropriate insights for characters with a modicum of mental ability.
But what I hear usually when the charismatic guy wanted a big bonus was that this party waltzes up to guards, with no thought or preparation, pulls his hood over his head, and the
player start talking like said pilgrim, and expects to fasttalk as if he were the next coming of Obi Wan, complete with hand motions.
I doubt anyone has any problem with the former. The latter, while not "bad wrong fun," is definitely something I don't want to waste my time on.
I like clever, insightful, and imaginative play that changes the situation and then the characters deal with the situation as it now is. This to me is the heart of play. I don't like
players fast talking their
characters out of problems, and I don't much care for the "too clever by half" equivalents for intelligence or wisdom, either.
