Quality Over Quantity
Socialization should not be based on quantity, instead it should be projected on quality. Being surrounded by a large number of children increases the chances of picking up inappropriate behavior and other negative notions that can affect one's well being. A homeschooled environment removes the chances of being exposed to negativity and helps parents focus on the child in a more isolated manner.
Every child will face adversities both internal and external, allowing your child to be homeschooled gives them the opportunity to stay away from other potential issues.