There was no mistake. Benjamin planned to spread magic and disseminate education in Desert City.
Magic was very much a talent-dependent skill, but in that day and age, it was not just talent that determined whether or not one became a mage, but also chance. Being recognized by a teacher, or coming across magic knowledge by accident and being self-taught, slowly journeying onto this path— this luck-dependent and ineffective method seemed, alas, to be the only way to become a mage.
Under these circumstances, even if a person had the talent, if he forever lived at the bottom of society and had no contact with spells, his talent could never be uncovered.
Therefore, Benjamin believed that this model could not catch up with present time prolificacy. It was time to change.