Special education sounds like a privilege for kids who are too good for regular education. Or at least that’s what it’s trying to do.
As every schoolyard bully knows, you don’t need forbidden words to hurt people. But once a word is forbidden, it becomes the quickest, easiest, laziest way to inflict pain. Also, any word can be co-opted for bullying purposes.
Special education and its sister term, “special needs,” were invented by well-meaning people who don’t like to think about what a horrible pain in the ass it must be to have Down’s Syndrome or autism or a severe learning disability in a school that isn’t set up to teach anyone too far afield of average. A side effect of using the same words to describe people with many different neurological conditions is that it might not occur to you to ask who benefits most from teaching them all in a single classroom.