(This is directed at the folks who continue to appropriate from closed/initiatory traditions, not at Cat)
A lot of people don't seem to realize that, in many cases, it's impossible to accurately recreate the practices from closed/initiatory traditions without the proper guidance, training, empowerments, spiritual contexts, and so on. Instead, what they are creating is a pale shadow of the real thing. That's partly why cultural appropriation is so harmful: If the pale shadow is heavily popularized to the point that it is equated to the real practice, it's much easier for the real practice to become forgotten or twisted over time.
Appropriation is also different from inspiration and cultural exchange because appropriation is ultimately destructive and operates without the consent of the living culture.
Cat_LeFey