Before Taekwondo, I studied Shotokan Karate. Our Shotokan roundhouse kick consisted of lifting our kicking leg up like a dog about to pee, keeping our hips square, with our knee pointed forward, and then snapping the lower leg out, making contact with the ball of the foot. It was described as a horizontal front kick. That kick never got used when we sparred. Then when I studied Taekwondo and Hapkido, I learned a different type of roundhouse. If I had continued to do roundhouse kick like we did it in Shotokan, would that be watered down?
"Watered down" in my mind means that something has lost an aspect of itself. Because they are merely different identities, I don't see how it is watered down. Especially since an art like Shotokan has evolved in a different direction than Taekwondo has. Certainly few would argue that Shotokan had some level of influence on the initial development of what has became known as Taekwondo, but the two have both evolved in two distinctly different ways.
Because I practice a curriculum that predates the Kukki curriculum, I cannot see how something I do could be watered down from a kukki curriculum since the two diverged into two dinstinctly different styles. I don't see that one is superior than another, one is more watered down than another, but they are just two different things at this point.
Watered down to me would be a
loss of transmission from generation to generation. For instance, a particular SD technique that was not taught to a student, who becomes an instructor/school owner and therefore never passes it on to his students. This would be watering down the art, because it has effectively lost a technique.
Another example would be a watering down in tradition, losing the two handed handshake, the bowing, the use of sir/mam. These things water down the structure of the art, because they are effectively
losing a part of the tradition.
This is merely my interpretation of what watering down means. I'd be curious as to what other people feel water's down an art.