Why does everything have to be 100% accessible?

I'm a prof. When I have a student with special needs in my class, the administration tells me ahead of time. I make the necessary allowances - and those differ from case to case, anyway: whether it's extra time in exams, or someone who is deaf, or someone who is blind, or whatever.

When it happens, I make the necessary allowances. When I don't, then...I don't.

The obsession that everything has to be 100% accessible, for every kind of disability, all of the time? That's just nuts, not to mention a complete waste of resources.