I have trouble understanding where the ‘only 17 people could read and write’. Who taught them and do not traders need to read and write in order to partake in business transactions. Hence, the city of Makkah, a CENTRE of global trade, needed literate people.
When poems were put up on the Kaabah walls who read them? Who wrote them?
I believe the illiteracy of the people has been grizzly exaggerated by the Muslim historians (another oxymoron).
Was the Messenger illiterate, I think not.