"I don't think [name suppression lapsing] is going to make any difference to those who have suffered."
Barnett said businesses had closed because of the threat, which came shortly after the botulism contamination.
He said he remained "more than angry" about the damage Kerr caused.
"Some of these people have lost their businesses and their assets because of one fool."
He said he hoped the court imposed a sentence that was a strong deterrent.
Meanwhile, two conservation companies are emphasising their distinction from companies run by Kerr.
Connovation Ltd and Connovation Research Ltd released a statement today to emphasise that the companies are not connected to Kerr in any way.
The High Court heard today Kerr was earning royalties from a product called Feratox - an alternative to 1080, but was in serious financial difficulties at the time the incident unfolded.
"There is an unfortunate similarity in the names of our companies and the former names of his companies used at the time of his offence," Duncan MacMorran, chief executive of Connovation Ltd said.
"We reiterate that our two companies are entirely separate and distinct entities from his businesses."
"We utterly condemn him for his inexplicable act of stupidity," MacMorran said. "We are delighted the police have brought their investigation to a successful conclusion."
MacMorran called Kerr's threats "abhorrent" and it was "distressing in the extreme" that the two companies' reputation could be mistakenly clouded by his acts.
The Crown and defence are disputing various elements of the case.