Most schools are not good places for disabled kids. Often, this fact is used as an excuse to exclude kids from mainstream schools. (Even though special needs schools aren’t actually better, they’re just separate).
People will say, in a tone dripping with compassionate condescension, “We feel that your child would be better off somewhere more prepared to meet their needs.” This usually makes them go away. It does not often result in their needs being met.
After that conversation, the disabled kids tend to go somewhere else and be someone else’s problem. Often in a self contained special needs school. This conveniently allows the mainstream school, and often the child’s community, to continue ignoring them.
They can pretend that the excluded children are in a wonderful place, surrounded by experts who know how to help them. It’s almost never true — the place “better equipped to meet their needs” is almost always imaginary. Segregation creates the perception of expertise; it does not create expertise.
Sometimes the expertise a kid needs flat-out doesn’t exist yet. There are a lot of people who need supports and teaching methods that have not been invented yet. If what they need doesn’t exist, their needs aren’t going to be met no matter where they are. Excluding them allows others to avoid having to face the reality of how awful things are for many people with disabilities; it doesn’t get their needs met.
Special education is not special, and special educators are not high level experts who know how to teach everyone. Special education settings are generally full of behaviorism, behavior plans, and low expectations. When special educators have real disability expertise, it’s because they’ve made a focused effort to get it. It doesn’t happen automatically as a result of training or professional experience. General educators can do that too.
If schools wants students with disabilities to be in “a place better equipped to meet their needs”, they have to work to become that place. There are no viable alternatives. Making people go away doesn’t get their needs met. Working to meet their needs does.
(Edited to add: It’s more complicated than that, and there are things I don’t like about this post. I think it’s more true than not, but there’s things it doesn’t cover, and I’m planning on writing some followup posts about it which will hopefully cover more ground.)