Corporations are made up of humans and are, fundamentally, owned by people.
It should still be necessary that the State let people face their accuser before the State uses its monopoly on violence to deprive people of their property via the judicial process. Otherwise, I can think of all kinds of methods that a corrupt executive or judiciary could leverage against poeple ("we're shutting your company down." "Wait, why?" "Anonymous whistleblower. Definitely not because you're contributing legally to a PAC that's making it harder for the President to get reelected.")
Note that here I'm assuming that the whistleblower's participation is necessary. I think you are assuming a more happy path where the whistleblower can nudge the State in a direction to put more scrutiny on a company that they don't realize is a problem. That already happens and sometimes works, but we also have whistleblowers because only they have access to internal documents that the company has chosen not to divulge (legally or illegally). When the case hinges on those, it's still quite just that if the State says "We're shutting you down because you replaced door plug bolts with chewing gum," the accused has the right to say "What? Who the hell is telling you we replaced door plug bolts with chewing gum, and what evidence do they have?" Because without that back-stop, it's just the government presenting evidence that they got... somewhere... and that's open to even more abuse than the status quo.
It should still be necessary that the State let people face their accuser before the State uses its monopoly on violence to deprive people of their property via the judicial process. Otherwise, I can think of all kinds of methods that a corrupt executive or judiciary could leverage against poeple ("we're shutting your company down." "Wait, why?" "Anonymous whistleblower. Definitely not because you're contributing legally to a PAC that's making it harder for the President to get reelected.")
Note that here I'm assuming that the whistleblower's participation is necessary. I think you are assuming a more happy path where the whistleblower can nudge the State in a direction to put more scrutiny on a company that they don't realize is a problem. That already happens and sometimes works, but we also have whistleblowers because only they have access to internal documents that the company has chosen not to divulge (legally or illegally). When the case hinges on those, it's still quite just that if the State says "We're shutting you down because you replaced door plug bolts with chewing gum," the accused has the right to say "What? Who the hell is telling you we replaced door plug bolts with chewing gum, and what evidence do they have?" Because without that back-stop, it's just the government presenting evidence that they got... somewhere... and that's open to even more abuse than the status quo.