What were some reasons renaissance humanist writers gave for writing in the vernacular

The correct answer to this open question is the following.

In the Middle Ages, just the aristocracy and the clergy knew how to read and write. They were the only ones who could access education.

But during the Renaissance, more people could access to basic education. So writers of this time though that Vernacular was the common language spoken by many people so a good way to spread their work was to write in vernacular so many people could read it.