When you put someone in a classroom and don't pay attention to who they are and their needs, you aren't including them, you're erasing them. This is not to say that you should separate; it isn't to say that "separate but equal", is superior. Separation, segregation, refusal to teach some students while you teach others, causes an enormous number of problems. But, taking someone and sticking them in a classroom and ignoring who they are ignores their existence. It causes problems, while only solving some of the problems of access.
It causes people to break, as they become pushed, further and further, through the inconveniences of their existence, aware of the "problems" they cause to others. It causes people to fail, lacking assumed background, assumed cultural reference points, assumed ways of being; because "everyone knows those things", even when "everyone" means "people like me".
When ignoring the students you have, rather than the students you want, the students you expect, or the student you were, you're preventing these kids from getting educated. You're denying education, just as if you'd denied them entrance to the classroom. You're allowing them to be there, but denying them the ability to access the material. Refusal to acknowledge differing needs, differing backgrounds, differing experiences, means refusal to allow these students the possibility of getting the same education the students you expected are being provided.
Instead, we must recognize the differences in our students. And we must do better than recognize these differences, we must do better than praise ourselves for allowing students to enter our classrooms when they are different. We must do better than praise ourselves for being "aware" of these differences.
We must recognize the differences in our students - and what these differences mean. We must take these into account, and interact with people how people should be interacted with. We must respect people, listen, and not assume that there is only one way to approach any given situation. We must challenge ourselves to do better.
Because, when we only teach one way, we aren't helping any student. We're not approaching education as a way to teach individuals; we're approaching it as a way to spread a message. Kids get hurt. Those who are already at a higher risk get hurt more, as they're already farther from the "average student" the lessons are built for. And the more people learn that they aren't learning in school, the more they don't learn in school.
No, we need to do better than that.
We need to listen, and learn, and teach, and pay attention to the kids we have. The kids that are there. Their baggage and silly behaviors; their backgrounds and methods of thought. Whoever it is that shows up, that's who we have, and that's who we teach.