They built a 9k stadium at Hutt Rec when the team was playing great football and was top of the table and couldn't sell it out.
They got more than 10k at Wellington stadium the game before those three. So, although the atmosphere was great and the team was playing exciting football and topping the table, they never sold out the makeshift stadium. The crowds started down and dropped as the novelty wore off. I wouldn't underestimate the hit to crowds that taking the team out of Wellington would do.