A minor point here, and without being judgemental: how long does it take to get the Bujinkan BB in Japan?
I've heard figures of 1 - 2 years being realistic. If this is true then it doesn't really make sense to run through 10 kyu levels in that time. It would mean 1 exam ever month and a half. That really doesn't make sense. Especially since there is no fixed curriculum so there is nothing tangible to distinguish the test for 4 months vs the test for 6 months. and kyu levels are much less expensive than BB levels, so from a monetary pov, having no kyu levels and 15 dan levels makes the most sense for raising money.
Again, not making a judgement here. Just pointing out that the lack of kyu levels does not mean anything, one way or another, regarding that specific point of the argument.