I thought most Kiwis backed the underdog, particularly the rural/country town underdog, and that was very much Qld when Origin was shown live on TVNZ in the late '80s.
Then Graham Lowe coached the Maroons, made him an honorary Qld'er when he won the dramatic 1991 series (and look at the match-ups - NSW had the superstars, Qld the battlers) and it became the done thing to support them.
I personally peaked supporting the Maroons in 2001 (when Alfie flew back for the game 3 decider) and NSW were a very unattractive football team (don't read any sexual innuendo into that last setence).
It was only two years ago I was pumping my fist for the Maroons but last year something happened. I switched, fed up with the five year winning streak. I can't stand Qld as a state and will never live there again, and their players aren't very appealing now are they? Who could get exciting over Cam Smith, Thaiday, Thurston, and the traitor Inglis, et al? Who could get excited over Qld'ers per se?