The difference is in the first line:
The speed cameras are coming down in Arizona, the pioneering program having failed to live up to its promises either in terms of traffic safety or revenue.
There has been no such publicly stated (AFAIA) goals in NZ and so no test against which their success, or otherwise, could be measured. In New Zealand, our law makers seem to take the approach of 'We don't really care if it works or not in New Zealand, we are going to do it anyway....trust us'. Compare this with a prudent approach of 'It has shown to have worked overseas but lets put some actual measures around defining if they are a success. If they are not, then we will remove them'
Given that a) There has been no real admission that Speed cameras are used to gather revenue, no such easily measured targets could be set and reported against to determine their success
and b) that the law making culture seems to preclude saying 'we dunno if this will work or not but we will give it a try' I think speed cameras are here to stay (regardless of their actual impact on road safety)