While I don't doubt that your kid was hilariously unappreciated from the school based on one test, I was a relatively lazy middle school student, scoring B-C ranges on most of my classes as well as pretty much failing the first aptitude test (pretty sure it said that I should be a truck driver). As a result, I wound up getting placed into non-honors classes freshman year. After a few weeks of finding the classes mind-numbling boring, I offhandedly mentioned to my advisor that I wanted my classes to be more challenging, and she immediately moved me to honors courses because of the fact that I had taken the prerogative to tell her that I wasn't being sufficiently challenged. Currently I'm studying Computer Science at a large state University.
Because both our examples have an n = 1 sample size, it's definitely not correct to generalize high schools across an entire nation. However, in my experience, high school advisors were more than willing to toss out aptitude test results if the student had taken the prerogative themselves. While I agree with the idea that "Every school is essentially 2 schools", the barrier between them is honestly so low that it's not realistically a problem.