There are lots of symptoms and consequences, but the core reason is the simple fact that people don't want their child to be put at a disadvantage; consequently they are reluctant to a) experiment on their own child with an innovative program, for fear it will disadvantage them or b) allow others to experiment with innovations that their own child does not have access to, for fear it will give the others an advantage.
For a public school to innovate requires them to first overcome a) by showing clear evidence that the innovation really works (not easy when you're talking about educational programs that take years to bear fruit), then overcome b) by implementing the innovation broadly enough for everyone to participate (generally much too expensive for the community to support). All the other usual scapegoats (unions, standard tests, Texas textbook companies) are marginal influences compared to this pervasive feature of human nature. As usual, we have met the enemy and he is us.
For a public school to innovate requires them to first overcome a) by showing clear evidence that the innovation really works (not easy when you're talking about educational programs that take years to bear fruit), then overcome b) by implementing the innovation broadly enough for everyone to participate (generally much too expensive for the community to support). All the other usual scapegoats (unions, standard tests, Texas textbook companies) are marginal influences compared to this pervasive feature of human nature. As usual, we have met the enemy and he is us.