An "Ideal" system would understand the critical important of the early grades, especially when it comes to establishing literacy. Preschool and Kindergarten are not just day care centers...they are places to develop certain skill sets before 1st grade to facilitate reading (like building vocabularies). Teachers and schools need to be held accountable for their student's ability to read in the early grades. It is beyond irresponsible to advance students who are not even close to meeting grade level standards.
If you don't learn to read properly in first and second grade, your ability to pick up math, science and writing skills in middle elementary is compromised. By High School, your confidence is shot, you are more than one grade level behind, and you might get left behind. Proper K-3 education is critical.