To me, though, in order for something to be classified as a martial art, it should be martial in nature. This means that it should have at the very least combative application, if not actively training for combative scenarios. When training for survival and combat, efficiency of motion is paramount and simplicity is key. There is no combative application for flips, cartwheels, rolling the weapon around your neck, etc. Now, those that defend the validity of such training say that it falls into the "art" portion of martial arts. However, I'd like to demonstrate how even that is a misinterpretation of what it means to be a martial art.
The traditional characters for martial arts are written as 武術 and pronounced as Wushu in Chinese, Bujutsu in Japanese and Moo Sul in Korean. Because I am primarily a Japanese practitioner, I'll be referring to them as Bujutsu for the remainder of this article. The first character, Bu 武, refers to martial, war, military and combat. The second character, Jutsu 術, is most accurately translated as skill, technique or craft. All of these are alternate interpretations for the word "art." So while Bujutsu can be literally translated as "martial art," it is most accurately interpreted as "skill of war."
In our Western mind, art is something we refer to as a catch-all phrase for pretty much anything and everything. You can get away with just about anything as long as you call it "art." While there is a degree of personal expression in Bujutsu, the word art in this context is not a catch-all. It does not give validity to whatever you want to classify as "martial arts" with the excuse of it being artistic. Even Aikido, one of the most aesthetically "artistic" expressions of Bujutsu, has combative application (albeit not widely practiced).
If you go to any large martial arts tournament, you'll notice that the divisions are split for traditional and creative expressions of kata and weapons kata. This is a step in the right direction, in my opinion, but there should be no such thing as "traditional" martial arts either. We use the word "traditional" to describe something old, something dead, something preserved like a museum artifact. While there is a distinction between classical and modern systems, and both should be equally respected in their own right, the connotation and underlying implication when someone mentions "traditional martial arts" is often that they are relics of a bygone era with little practicality in the modern world. But tell me when we've evolved as human beings? Have we grown another limb? Has the location of our joints and vital targets moved? All of the techniques in "traditional" martial arts can be and are still practical in a modern, combative scenario with the right training methods. A punch is a punch, a kick is a kick, a lock is a lock, and a throw is a throw. To me, a "traditional" martial art is one that is taught alongside the culture and rituals of the country of origin for that particular art. It has nothing to do with age.