When I was in 1st grade, we had an autistic child in our class. He was not very verbal, and he did have a lot of behavioral problems, but he was capable of communicating at a precocious level in other ways.
We had the main teacher, and then we had a special ed teacher who accompanied him to our class and could handle him if he was having an episode. It worked out pretty well. He was no more disruptive to the class than the rest of the kids, overall. You know who the most disruptive kid in that class was, actually?
It was the mid-90's, and there wasn't a lot of help for kids like me. No learning disability, not autistic, very bright, but with other problems (in my case sensory integration disorder and other things associated with highly sensitive personality, and bright children - these things go hand-in-hand for a lot of kids). They had no idea what to do with me or what was wrong.
If they'd had any idea what to do with me, apart from try to stick me on Ritalin (which my parents refused because I had no attention deficit, and I was not hyperactive, I was just overwhelmed and acting out), I probably could have been helped quite easily by sensory therapy. We have that now for kids who are like I was.
We didn't have it back then. Or at least, the awareness wasn't there back then.
I gradually adjusted as I got older. But I had to do that on my own. I didn't find out what the problem was until I was 19 years old, when I was going to therapy for some other stuff that had happened in my life lately. It tends to get worse when I'm severely stressed, so I was having more problems with it than usual, and my psychologist caught it.
But by then, it wasn't very relevant. Knowing that at 19 was not going to help me with school when I was in 1st grade. My life may have turned out differently if someone had figured it out when I was 4, like they do with kids now, instead of when I was in young adulthood.
As for the autistic kid in my class? We got on just fine in that class even with him there. He had the help and personal attention he needed. And we, the students, got imbued with a sense of empathy and understanding for people who are different.
I went on to volunteer to play with special needs children when I was in 4th grade. Some of them were profoundly disabled. For some reason, although I was far more "normal" than they were, I could always relate to them. I looked normal and I could stumble my way through the normal world alright, but there was a part of me that understood when they acted out. I may not have known exactly what they were feeling or thinking - they couldn't always tell me - but a part of me knew that this wasn't so different than what I'd felt. Just much more extreme.
I think spending time with them did more to help me than any teacher or doctor I ever had.
The point here is that mainstreaming is not the enemy. But mainstreaming ignorantly is not going to work well. It is not a contradiction to mainstream and simultaneously give personal, empathetic attention. We can do both those things. It helps the child, it helps the teacher, and it helps the rest of the class. Educationally, empathetically, and in terms of personal growth and maturation, everybody wins when we give special need kids a sense of normalcy and also teach typical kids that they are people too.