Monty Roberts, horse whisperer, in his book says living beings have two responses to a challenge — fight or flight.
Parents, on the whole, I find would rather flee than be involved in confrontation. Sure, they want to advocate for their child, but if they have a choice, they will leave.
Far too often advocating or just asking simple questions the parents is made to feel inadequate or simple-minded.
On the other hand, I think teachers and the bureaucracy are "fight" minded. They defen or rather seem "defensive"/
Public education is really a scarce resource, and any extra but needed services are rationed out. They usually go to the insiders first.
These are some of the reasons we need a lot more choices in public education.