Here's my two cents.
From my personal point of view that juggling is a unique art form.
Art is about creation and the expression of something unique, that cannot be expressed in any other way than in the particular form it takes in the work being presented. This is why each work of art takes the form it does – there is no other way to express what wants to be expressed.
The people who create are the ones that push and develop an art form further. They are expressing something about themselves and the world in general. This „something“ is what resonates and touches the onlooker/listener/etc.
A tried and valid way to learn any art form is to copy the work of masters. Where it get’s uncomfortable is when there is no mention of where the material came from. When there is no context, there is no respect.
If Reajan or his son (or any other copier) spoke in their performance about the originator and his work, how he developed the triangle and his very concious artistic processes, if they informed the audience about the context of the pieces they show then i would have no bad feeling about them doing it. Then it would be a celebration of the original creative impulse. The audience would feel this and appreciate the work even more.
If there is this lack of context given to an audience, the general public will watch the routine and think „wow, that guy had a genius idea, he must be a super creative person to have thought of that“. The copier then feels smuggly clever whilst conveniently ignoring the fact that he’s completely lying. This pisses me off greatly.