Why didn’t King, Jack, Queen, and Who's-Who want to copy Kaidou's Thunder Bagua?
Yamato copied the Thunder Bagua, and King "copied" the Flaming Dragon.
This topic lacks a solid foundation. There is no clear information indicating that Rayleigh tried or wanted to copy any specific technique of Roger’s, like the Kamusari. Without that evidence, any assumption about him wanting to replicate Roger's abilities is purely speculation.