I think some of you are confused about the real motives of NCLB and the standardized testing push of the last 20 years or so. Do a little research and you'll be amazed at how many elected officials/families/friends have financial interests in testing companies.
And I really don't think the concept of social justice was considered much when the public school system was established in the US. The simplest answer is one from an early post- it is a system that works (relatively) well for the vast majority of students. The outliers on both ends are hurt by that kind of a system, which is why more flexibility is needed for those kids.
