I think it is reasonable to expect regular classroom teachers to provide for the needs of a child with disabilities in their classroom to a certain extent. I think regular education teachers should include children with disabilities into their classroom even if it makes their job harder. The reasons for not including a child with disabilities cannot include personal problems on the part of the teacher. The needs of the child must be the most important factor.
According to IDEA, each child has the right to be placed in the least restrictive environment and a right to an appropriate education. The students education must appropriate to their individual strengths and needs. The student has the right to have access to general curriculum with non-disabled children. These rights may mean that the child needs to be included in the regular education classroom, and a regular classroom teacher must provide for their needs. However, these teachers can not go it alone.
The teachers should provide for these children, but with the support of other professionals. The teacher should not be the only person responsible for the needs of child with disabilities. The regular education teacher should also be trained in providing support for the childs disability. Much of their feelings of being overwhelmed may be due to their lack of training and resources.