After Dunne's shock announcement the Green Party entered the race, standing Tane Woodley, in a bid to get as much of the party vote as possible, but in doing so have made it harder for O'Connor to win.
In his newsletter, sent out today, Dunne said he now observed the news media rushing breathlessly from one photo-op to the next, "pontificating" about trivia.
"All the while allowing themselves to be manipulated by the absolute worst of politicians focused on nothing more than their own promotion.
"All this furious activity, chasing political leaders up and down the country, from one day to the next may be great for Air New Zealand, but does nothing for the carbon footprint or the credibility of the political process as a whole. It has all the trappings of a circus rather than a serious democratic event by which we elect our government for the next three years."
Dunne said if that was his view only just over a week after he decided to quit, he could only begin to imagine how most voters feel.
"A world where the country's future is potentially determined by vacuous smiles or predeterminedly angry snarls is not for me. Policy debate is seen as boring or a nuisance which detracts from the drama of a succession of mini-scandals which pre-occupy the media."