Yeah… you're still thinking that all martial arts are the same, have the same ideals, the same emphasis, the same purpose, the same aims, and more… and you're wrong. This example is, to put it simply, rather pointless. Boxing, or at least Western Hands, is a large component of MMA skill sets… so of course they can box… not to the level of a pro-boxer themselves, of course, but they're hardly going out of their major comfort zone. Find me a guy trained only in MMA who can get through an Iaido competition and you'll have an argument.
The difference being that a MMA guy has never trained in the art of Japanese sword drawing. However, a Kung Fu, JJJ, or Karate practitioner should be trained in stopping kicks, punches, and grappling, which is what MMA fighting is. In other words, if a traditional martial artist can stop a wrestler in the street, why can't they stop them in a ringed arena?
And again, who says that traditional martial arts are unarmed…? As far as there being no reason that a system shouldn't be fully capable, yes, there are many, many reasons… ranging from mechanical, to cultural, to tactical, to strategic preferences, to, well, everything to do with the art in question.
What mechanic, tactical, cultural, etc. preferences would prevent a Praying Mantis stylist from being able to prevent a wrestler from taking them down and turning their face into hamburger?
Again, its a dubious argument to say that arts that present themselves as fighting arts, and promote their self defense attributes, cannot perform those abilities against fully resisting opponents from other disciplines because of rules or cultural limitations. Bjj, MT, Boxing, etc. come from different places, yet still work perfectly fine in a MMA bout.
Really? Which ones? I think you'll find that the "similar types of events" aren't really that similar…
Mantis kung fu came out of this;
Lei tai - Wikipedia, the free encyclopedia
There's more of course.
Really? They wanted to showcase their art, they helped set the whole thing up, they helped design the surface (too slow and soft for the strikers to really get the purchase, speed, and power they were used to), and picked the guys they were going up against… but you can't see how that proves anything? And TMAs are "primarily striking arts"? Not any of my TMAs, mate…
Even if all that's true, Bjj is still a staple of MMA competitions. So clearly there was substance behind the shameless promotion. Another way to look at it was that the Gracies were attempting to being legitimacy back to the martial arts after an era of frauds, scam artists, and shoddy practitioners. After the UFC, all MAs had a standard by which to be judged in terms of effectiveness. Some like the standard, some don't, but clearly the MAs are better because of the first UFC.
Going to the ground is a dumb thing to do… in the majority of contexts. In an environment such as the UFC/MMA competitions, it's not. Once again, this is not the definitive form of "fighting" you seem to think it is…
Dumb in what context? I can think of several reasons why going to the ground might be the smart thing to do.
Despite that though, don't you think there's a problem when a martial artist gets taken to the ground and is essentially helpless? Just because you don't want to get taken down, doesn't mean that there isn't someone out there that can't take you down.