Why was Leonardo da vinci homeschooled?

He wasn't homeschooled. He was an illegitimate child and in his time not accepted by society. He didn't attend school and never saw his father. In his late teens his father arranged for him to go into an artist studio and it is there his talents showed. Otherwise the world may never have known about him. As it was he didn't finish a lot of what he began or accepted commissions on. He was often sued for this.