It's not at all that poor kids who score low don't get services. It's that the school staff doing the evaluation decides if the reason for the low score is intellectual or socioeconomic. They figured that Sissy's delays were socioeconomic and that if she was mainstreamed, like an immigrant who had come from another country with their family and was an English language learner, that she'd catch up. The woman I was speaking with was very sorry since she was also one who helped make the decision. When she saw Sissy again this year as we got Blossom settled in school, it was plain to her that Sissy hadn't progressed and indeed seemed to have an obvious special need, yet she didn't say anything until I asked. She explained that Sissy appeared well-behaved (what that's got to do with intellectual disability I have no idea), cute and interested. She, of course, didn't realize she was looking at a child with RAD who attends to every stranger who gives her attention.
Special education does cost more money. The student/teacher ratios are lower and there is more staff and adaptive equipment, restrooms for special ed. classrooms for changing diapers and clothes, etc... A nurse comes to do feeding tube feedings and other medical treatments during the day, too. Some kids have personal aides all day. The system is designed to "weed out" rather than include any child possible. After all, if a child scored as low as Sissy did, wouldn't it be in the child's best interests to err on the side of getting her special education and then move her up if she made progress, rather than throw her into the mainstream and let her flounder before realizing a mistake was made? In our old school district, I was told that a child would have to fail for a YEAR before changes were made. I've since learned that the information I received from that district was incorrect. They'd even told me I couldn't have my kids evaluated without enrolling them. I was told this twice very firmly!
The bottom line is that these people truly want to help, but they are so overwhelmed with the numbers of students needing that help that there aren't enough hours in the day, staff and resources to get everything done. Our school district was fined by the State Board of Education last year for failing to provide speech therapy to a child who qualified for it. The reason the child didn't get speech therapy was that there aren't enough speech therapist and despite efforts to hire more, there is a state-wide shortage of speech therapists so there isn't anyone to hire! The system is broken. Each school is responsible for the evaluating of all the students who live within the boundaries of that school. Our high school has over 3000 students! There is only one psychologist on staff. The school has 60 or 90 days to complete the evaluation. With that amount of students and limited time to try and schedule all the different evaluators, many of whom come from other schools, like the speech therapist, it gets near impossible. I requested Sissy's evaluation in May and it wasn't complete until November and I had to keep on them and even push for the speech evaluation.