"This is pretty industry standard."

It shouldn't be, and didn't used to be (I'm 40 so I've been around software dev for a while).

This kind of behavior is unprofessional and an embarrassment for our industry if we just consider it our industry standard.

It doesn't take much effort to draft a form letter rejection (that is generic enough to avoid any potential for lawsuits, if that's their concern) and even less to send it out. With just a minor amount of work they could act like they were adult humans who treated other people like humans... why not do that?