The fact of the matter is that parents fill a more important role than Teachers in the majority of a student's life, Parents normally see the student more than a teacher, and give the student their overall personality and outlook upon things. If a parent is teaching their son to dislike math, then even the best math teacher may not be able to change that. The teacher merely gives the student a better chance to learn the subject at hand, by making it easy to consume and helping them along the individual bumps.
Students are often motivated by what happens at home. If students are happy at home and have motivation to do well in school, they will be victorious in school. Teachers are there to facilitate learning. In the end, a family determines whether or not a student is successful in the classroom and in life.