Chances are that if you are in your late 30s then your school wasn't implementing an "inclusion" program - I'm similar in age and I know my school didn't.

Currently schools are instructed to place students in the "least restrictive" environment possible. What this means is that students with disabilities, that in my day would have received pull-out services, are now spending their days in mainstream academic classrooms. This has proven to be beneficial to those students (in my opinion, the literature hasn't yet proven that it doesn't impede "mainstream" students) but in practice it means that instructors are now scaffolding and modifying material to meet the needs of ESL students, learning disabled students, behaviorally challenged students, autistic students, and more all in the same classroom.

It's challenging for a single instructor to handle the multiple different needs, paces, and abilities in a classroom on their own - quite frankly it can be extraordinarily challenging for an instructor, a para, and the occasional special ed teacher to handle a classroom of twenty-five to thirty students even with three adults in the room.

This is only one small piece of the puzzle, but Inclusion programs are where the current pedagogy is and there is plenty of literature to support it (and as someone in a classroom on the daily I'll admit that I'm not sure where I fall on the topic).