SEN too inclusive?

I have a five-year-old son with Down's syndrome who has a statement of special educational needs. He is very successfully included in the local infant school, as is a little girl with cerebral palsy. But as far as I can see, their needs are being lumped in with those of a motley collection of children who are simply out of control, undisciplined or badly behaved. SEN provision seems to have been hijacked to pay for crowd control in our schools.