Why are American university admissions so much more organized than American business admissions?
Easy answer: Application fees. And those who apply for free or for scholarships are essentially subsidized by someone else.
Hard answer: Universities weren't always organized. They used to be like businesses: highly patronage-driven. And they still are, due to legacy applicants.
But we're operating on a broken premise. Organized and polite recruiting does not correlate with meritocracy. Ask the Soviet Union or universities. Ask the huge megacorps who do reply to every job application.
Elite universities' organized legacy admissions undermine their claim that reading every application and responding to every student makes the process fair. I know corporate admissions worse, but my anecdotal impressions are the same. Patronage rules.
Making HR respond with rejections feels good, but it does not make the process more fair. Only attacking patronage makes recruiting fair. A lofty goal.