What really makes Aikido dilluted? Is it people wanting to change the art to suit themselves, and the way they feel it should be done? Or is it about those who dont fully understand the art; their knowledge is a product of passing through many, and thus they pass this dillution onto others?
I guess what we really have to look at are the main ideas that will always get passed on because they are essential to what Aikido is. I would think this would involve the basics and the concepts that go along with them. ex. chushin-ryoku, shuchu-ryoku, kokyu-ryoku, ki, irimi, kaiten, ukemi, kihon dosa, kihon waza. Although these principles and techniques may differ from person to person, the idea should still be there. Most importantly though, Aikido should teach someone how to connect the body, mind, and spirit and I would hope that this is something that will not become blurry over time. I believe that if these things are lost then it is not Aikido.
I think the art is safe though. Aikido, in my experience, attracts a certain kind of person. It quickly weeds those out who are not fully intune with themselves and others around them. It takes dedication, commitment, hard work, will to succeed, and a strong heart to develop in Aikido. Aikido is not for the faint at heart.