On the Chinese Invention of Writing

"The reason that late Chou pottery inscriptions resemble seal and coin inscriptions is probably that these were the writings of craftsmen and traders, people of different life station than archivists and historians who wrote with brush on silk and bamboo. Prehistoric and Shang potters did not necessarily have comparable status to Eastern Chou potters, but they were indeed closer to the common people than were the oracle and bronze scribes. As mentioned above, scholars have used the pottery inscriptions to discuss the great antiquity of Chinese writing. I see the significance of pottery inscriptions in the issue of the origin of Chinese writing also in this light: The invention of writing in China was more associated with social identification than with economic transaction, and it was initiated by the common potters rather than society's heroes and geniuses (such as Ts'ang Chieh)."

—K.C. Chang

I can well believe this—would like to see some more up-to-date writing on the question, and chances are (eventually) I shall.