Probably your patients.
I'm sure you didn't mean that statement the way it came across, but you should re-read it.
If people didn't care what nurses knew, then I doubt nursing schools would exist in the first place; instead, nurses would probably be trained in some kind of apprenticeship that varied from person to person, hospital to hospital, specialty to specialty. But someone cared enough to say that nurses need a basic framework of knowledge to begin practice and a license under which to practice. Hence, nursing school.
Most 4-year-universities are expensive. That's a problem. However, unlike medical school, which requires 4 years of undergrad work, plus 4 years of medical school, then residency, etc. A BSN would only require 4 years. Not entirely the same thing.
Which is not to say that cost isn't a valid point, though, because it is. But if ADN programs are eliminated, then all those scholarships and financial aid and such that were available to ADN students will then be available to BSN students, particularly if - as I suspect - BSN programs simply absorb ADN programs as satellite locations. Perhaps there will even be a reduced tuition offered for being wiling to attend one of those satellite locations.
Who knows? But problems like that can be worked out ... if everyone would get behind the idea of a standardized education entry point for nursing.