I agree that through years of experience and a general interest in children is definitely a requirement for being able to provide greart care but it still doesn't mean that home daycare is best for kids once they reach the preschool age.
Children who are preschool age DO need an educated provider/teacher in order to teach them academics. Someone without the deeper understanding and knowledge from an ECE degree is not necessarily qualified to teach children the academic part of learning in comparison to a home daycare provider.
I would think THAT is the line of thinking used by parents when they pull their child from home care and enroll them in preschool.