yeah we've always had more of a walk up croud. I honestly think that is partially to do with weather. Easier to commit to a season of games when you live in a warmer climate.
Supporters commit to a club, on a game by game basis or for a season for many reasons, but a warmer clime in terms of commitment is only relevant to fair-weather visitors.
Sadly the majority of people at any sporting event in NZ, with an admission price, are attenders or pot hunters not supporters/fans.
The walk-up croud is another myth propagated by the majority of the NZ media, who will not recognise that most people in NZ prefer to watch sport from home on a big screen. Other excuses include ticket prices, beer prices, food prices, quality of food and quality of beer
[ btw: preaching to the converted, not having a pop :-) ]
You forgot stadium shape and length of weekend.
The first part is the challenge I'm sure the owners are aware.
What doesn't help is the semi regular shark performances. The new punters goes to a couple of games of semi shark performances in a 16-20 % full stadium and the players are dots, can't blame them for thinking, nah.
This goes with the second part where are lot of those problems point to a better stadium for football and for the fans, supporters and entertainment seekers.
There was a pre-season "Meet the Season-ticket holders" session at RNYC, where one of the 'shocking' statistics was, the majority of occasional stadium attenders to a Phoenix game only go if they think the Phoenix are going to win. That wasn't presented as a condemnation of those supporters, just a recognition of the NZ culture of reasons for attendance at a live game of a team they support