There are modern and traditional Japanese Martial Arts, the modern are popular with those who like less discipline and less of a military atmosphere in the dojo. As Americans of high rank and experience leave the tradition and formalities of Bushido, they treat martial arts more like a sport. The martial arts are what we have left from masters of the past who depended on the skills learned in the dojo and practiced on the battlefield. We need to show respect for the ancient traditions of body, mind, spirit harmony. We do that by following the practice of the masters. Modern procedures should be called by a modern name, rather than give the impression that the ancient martial art is being updated.
Actually, the modern martial arts are far more militarized than the older ones. Judo, karate, kendo and aikido all were heavily, and badly impacted by the military culture of the 1920s through the 1940s. The atmosphere in dojos for all of the 20th century arts is very, very different from that found in the old, pre-Meiji arts. The modern arts (even Judo which is late 19th century, and Aikido which didn't really begin to flourish until the 1950s) all absorbed the military style of teaching martial arts that everyone who trained experienced during the period of militarization and war that made up most of the first half of the 20th century. These arts were taught in schools, and practiced by people who had learned them in school and military atmospheres, and the style of teaching and learning became quite colored by the military style.
The koryu budo ryuha have far deeper roots and never absorbed the military style of practice that infected the modern arts. The koryu budo were too small to be of interest to the government and the military, and so were able to continue their practices without government interference.
Also, please don't call it "Bushido". That referred to the way of daily life among the bushi, something no one tries to pass on. "Budo" is a far better term, and doesn't have the liability of being attached to Nitobe's horrible book that was an attempt to create a myth to rival that of chivalry in the West. Nitobe was so ignorant of Japanese budo history that he thought he created the word.