Re: What makes a style?
Why should it bother anyone? Well, I have one possible answer-a proliferation of "styles" especially by those not qualified to develop them will lead to the same problem we see in some of the other arts-where your rank means little other than in your own dojo. It's already happening where we are developing our own little "sokey dokey's" in the aikido world and calling themselves 10th dan grandmaster, soke, professor, doctor.
To me, a style should only evolve when something is unique in the interpretation of the art. That too could very well be viewed as simply an interpretation of that individual. Something truly unique. There are a lot of aikikai shihans that are unique and get dubbed as a style (Iwama, Nishio, etc.). Are they really a style or are they simply interpreting the art. As to those that break away, my impression is that it is generally political or ego-can't get promoted to the rank they think they deserve or simply cannot get along-so much for the art of harmony. Some like to blend in other arts which is ok if they hold some serious earned rank-such as Nishio.
I would really hate to see Aikido go the way of some of the other arts and get watered down and everyone in the world setting up their own little empires resulting in the art deteriorating to the point where rank becomes meaningless as a measure of quality or capability.