Earlier quoted context omitted.
The society used to care a lot less about special needs people.
There's a finite amount of tax money available, so disproportionately allotment to a few special children effectively robs the other children of resources.
In Finland and Singapore (two countries with education systems among the top in the world):
1) What's the percentage of education spending that goes to special ed?
Looking at Finland, we can find their total spending:
https://www.statista.com/statistics/538122/general-governmen...
and we can find ample evidence that they care just as much about special needs kids as the US does, if not more:
https://www.heischools.com/blog/finlands-approach-to-special...
What I'm having a harder time finding is: what percent of the education budget goes to special ed?