No, that is not convincing. Chinese style printing was widely used in Europe before Gutenberg. The key reason is that Europe had technologies already available which could be used to advance Chinese printing, while in China and Korea those technologies did not exist and thus anyone who would have wished to be a Chinese or Korean Gutenberg would have had to invent 3-4 key technologies from scratch before inventing the Gutenberg printing system. That is simply an implausible event. It has nothign to do with what people "think was necessary."

Invention doesn't really happen from some overall plan anyway. Inventions flow from use and need and draws from existing technology and practices. People living in Switzerland don't suddenly develop the most advance sailships. Technology evolves within some context. The Gutenberg system was a lot about metallurgy and it evolved the the most metalurgically active area of Europe: Germany. A plece full of metal workers, Gold smiths, clock workers.