The Wind Scroll is about discussing the shortcomings of other koryu. I think Musashi is referring to Tenshin Shoden Katori Shinto-ryu (since he studied it) when he mentioned:

1. "Schools that commercialize" martial arts (excessive number of sword moves are taught to impress beginners).

2. Shorter-long sword (since the bokken that is used in Tenshin Shoden Katori Shinto Ryu is only 38 cm. while in other koryu, it's 40 cm and up).

3. Calling the positions of the sword the formal techniques & transmitting the science as the inner teaching.

4. Martial art is viewed in a limited way (since its teaching is kept secret for outsiders, improvisation is prohibited in the koryu, you can only improvise after you reach the status of a menkyo (licensed instructor)).

5. Musashi also mentioned here: "I do not care for written pledges or articles of penalties.", since Tenshin Shoden Katori Shinto ryu follows keppan- which is a blood-oath of rules that if you break any of those, you will be expelled.

The other part is the shortcoming of wielding a very long katana. I think he was referring to his famous opponent- Sasaki Kojiro since he carried a very long nodachi called Monohoshi Zao or Drying Pole sword. He solely relied on his Monohoshi Zao that Musashi used it on his advantage by creating a suburito (http://en.wikipedia.org/wiki/Suburito) larger and longer than Kojiro's Monohoshi Zao. Thus, taunting Kojiro more aside from the fact that Musashi came late during the time of the duel (psychological battle). Musashi mentioned that not because the sword is long, it's already adaptable for long-range combat. To think like that is the weakness of the heart according to him. A long sword will gonna give you a hard time swinging and striking, especially in close-quarter combat. It will just be a burden to you.

When I realized it, I think much of the techniques in Hiten Mitsurugi ryu are really bad in military science or in winning real-life combat as were discussed in this chapter (although Hiten Mitsurugi ryu is a fictional style & much of the techniques are exaggerated in the manga-animé, they were based on real-life kenjutsu techniques) .

*In this chapter, Musashi said that he wants his students to put his lessons in their hearts and minds by understanding those, abandoning the bad aspects of martial arts so that they could enter "the real science" of warriors and they could be free of doubts in real life combat.