I agree. But sport competition is not the only way to "keep the art honest." There were karate experts way before it was even imagined as sport that I am sure would give any modern kick boxer or karate champ more then they could handle.
The key word here is "were". It should also be noted that karate experts of old didn't shy away from exhibition or public fights, and even criticized other karate masters who shied away from fighting. Motobu Choki and his attitude towards Funakoshi being a prime example.
We do not train for sport at my dojo. We train to do damage to our opponent, not score points. We do kata to develop basic skills and principles, as well as those movements that are practical in a modern fight. (I will admit some kata moves are not practical nowadays, but there is more to them than most people realize.)
You may be surprised to hear that we do the exact same thing in BJJ (minus the kata), yet we still find time to train for competition as well. Interestingly, the guys who compete tend to end up with a higher degree technical skill than those who do not.
Most of our training involves grabs, arm breaks, knee breaks, elbows, other assorted strikes and a few kicks to low targets. KISS. We strike (and "block") in a way to inflict additional pain and damage. We work on maintaining control from the start to limit/eliminate counter attacks. Two man drills while padded up allows us to actually hit and get realism. And most important of all is the mental attitude that is developed that a street fight these days is definitely NOT SPORT.
Yeah, but is that Isshin-Ryu striking on Isshin-Ryu striking? Is that sparring or drilling? How much innovation and alteration is allowed in your drills/sparring? After a certain point, style on style drilling begins to dull the overall system, and it begins to fall behind.
One of the reasons I said that MMA keeps BJJ honest is because MMA constantly evolves, thus forcing BJJ to evolve with it since BJJ is the core submission grappling art of MMA. Within that, you have BJJ being constantly exposed to modern fighting systems like Boxing, Wrestling, Combat Sambo, street fighting, etc. In addition to that, non-MMA BJJ is very open to wrestlers which also bring a lot of innovation to BJJ itself, and that keeps the art "honest" and constantly evolving.
One example of this was the recent Catch vs BJJ bout that took place between the CACC "champion" Curran Jacobs and random 10th Planet BJJ blackbelt Quentin Rosenzweig;
Why is this important? Simple; BJJ exponents have incorporated elements of Catch into their game, and then evolved beyond that to elevate both the sport and the art to levels where catch simply cannot keep up. BJJ has the added benefit of far more practitioners and a far more open culture of innovation. Catch on the other hand is working from a handicap in that they're working with far less practitioners and are actively avoiding incorporating BJJ into their system because (above all else) they want to be a separate system from BJJ. So the results speak for itself. Considering that Jacobs was supposedly the top catch guy around and he got easily beaten by an unranked Jitz guy was quite an upset for the CACC community.
A modern respected karate "Grand" Master has said, "True karate can never be sport." If one understands what this means, they will understand sport is not the only way to train for effective fighting. But minus the type of training I've outlined above, competitive sparring is better than no sparring.
He's welcome to his opinion, but effective fighting is evolving constantly. If you're still doing one steps from the 19th century, you're well behind the 8-ball. Judo understood this, which is why Jigaro Kano in all of his genius incorporated modern
sport wrestling and grappling into his modern Judo system, and then proceeded to replace classical Japanese martial arts with more modern systems. Why? Because Kano understood that the toughest fighters around were modern wrestlers and boxers and they were handily beating experts from classical MA systems.
Given that over a century later, a lanky Brazilian using a modified version of Kano's system forever changed the course of martial arts in a NHB event kind of speaks for itself.