In the definition of martial arts, are all of them arts for being martial? I don't believe Tai chi chuan is, but I cannot think of any other. Here we could say is a change of intent. The forms are still somewhat martial, but performed for health reasons. But could Tai Chi practitioners use those forms for combat? Probably not nearly as well as most other schools. I've never heard of Tai Chi combat competitions. What do you think other martial artists would say, if the dictionary definition became: "Martial Arts are exercises for health and longevity" and then used as examples: aerobics, yoga, and jazzercise along with Ju-jitsu and Tae kwon-do?
Since Tai chi chuan literally translates as "supreme ultimate fist" (or a variation on the theme) and it was developed as a means of self defense in the early nineteenth century. It's (very) somewhat analogous to Akido. Modern instruction and modern forms tend to emphasize the spirituality and exercise aspects far more then the practical, but the style is still capable of being an effective defense. It's is a
different defense then more typical hard or hard-soft martial arts, based on the premise that the best defense is to passively accept and redirect violent acts around the practitioner, rather then to block or intercept them. It's also worth remembering that tai chi chuan in combat or a martial floor display is much faster then the meditation and exercise routines.
I think there's an analogy there that relates this back to the debate at hand, but I can't quite phrase it. Something along the lines of: Tai chi chun:Shaolinquan (the broadest and best known hard Chinese style)::narrative/storytelling:simulation/gamist. Or something.
As for myself, I'm in the camp of challenging both the stats and the player. Part of this is preferred playstyle, and part is one of my groups. One player is a salesman by trade, and a good one. He's probably the smoothest, most charming person I know. He alternates between playing smooth tricksters (himself, really) and oafish brutes. When he's playing a brute and tries to be suave and charming, he gets a bonus based on whatever his role-played and acted line of bs is, but he rolls the character's social skill. He rolls when he's playing a charmer, too.
On the other side of the table, I have a player who is extremely shy, a little socially awkward, and quiet. She likes playing charming, socially adept, Machiavellian tricksters and rogues. If asked to get up and do amateur theater, she'd refuse. Drama would probably occur, but having a player break down in tears and leave is not the sort of drama anyone wants. She gives a abstract of her character's goals, I give it a penalty or bonus based on it's impact on the target and she rolls.
If I just had them role-play/act, I'd have Gronk the 'Special' Barbarian (Low INT, WIS, and CHA) pulling off cons that make the Sting look amateurish, and I'd loose another player entirely. On the other hand, if I just rolled (which I admit I do some times for simple things like haggling with the bartender or whatnot) then we'd miss some of the better lines of BS from the salesman and the cunning logic and manipulations from the shy player.