My wife's sister is a teacher, too. I agree that defining that response is the problem. Especially for behavioral issues the balance you note is important. That's why extreme cases (e.g. non-verbal, violent meltdowns) are allowed to be segregated from general education classrooms when necessary.

We don't begrudge wheelchair bound students ramps to access rooms. We shouldn't deny children with "${diagnosis}" driven behavior alternatives to punishment when it's appropriate.

Edit: For what it's worth, I also think punishment is too often a first-resort by schools for all children. This is a complex issue driven in part by the horrific way we under-fund schools. Many of these problems would be much less significant if we funded schools well enough to provide the support they should (and are legally required to).