I am unable to confuse "seeing" a disabled person and having one thrust at me.
Would having this family ring your doorbell so you can be "more civilized" clarify it for you?
The effect on children being forced to ask what is DNR seems to be lost on you. I would rather not have you or any school decide for me when is the proper time to discuss mortality and death with my own children.
You are offended by the presence of a disabled person in a public space. Enough said.