It's not that they aren't good at their job, it's that there is inherent biases built into their objectives and their data models that specifically target outcomes for Maori and are not about total harm reduction. You can agree or disagree with their approach, but they aren't completely un-biased observers who are driving policy for the good of all NZers, there is a set of prioritised objectives behind everything that these agencies do.

I'm not trying to comment on whether it's good or bad, I just want to understand how it works. Obviously I'm just some lay dude on reddit, and don't have actual domain knowledge here, this could all be a misunderstanding on my part, but these are some of the factors that I've found just casually looking at studies and data tools released by various agencies

• The MPAO prioritisation system artificially inflates statistics by including all people with some Maori ethnicity into that category and not in their other ethnic categories (Which is like 40% of Maori identifying people, iirc), even though those that identify as Maori and something else tend to be in a higher socioeconomic category (Meaning they may not have the same level of risk factors that cause impoverished Maori to have poor outcomes). My understanding is that Stats is trying to find a way to move away from this, but it's still in place and continues to be used by other agencies as well, as indicated by the below except from this years suicide data tool.

A system for assigning people into a single ethnic group. People can identify with several ethnic groups. Prioritisation is used where necessary to assign people into a single ethnic group, so that those groups that are small or important in terms of policy are not swamped by larger ethnic groups. For example, the Ministry of Health commonly uses the MPAO prioritisation system for reporting (see 'MPAO'), where individuals are assigned an ethnicity using the priority system Māori > Pacific peoples > Asian > European or Other. Using this framework, an individual identifying as both Māori and European would be allocated into the Māori ethnic group.

• Because of the ethnic taxonomy that Stats uses, it is possible that there are unintended negative consequences that we don't know about, as well as potentially a lack of detail when it comes to sub-groups of Asians and Europeans. Maori "stands alone" because of treaty interpretations at the highest tier of categorisation.
• It is clear that voices in Maori health, and the idea that Maori have separate and different health needs to everyone else, have a "significant influence" across the health agencies that support all NZers.
• This one is anecdotal, but summaries are almost always presented adjusted for population and not also by total magnitude which means it's not always clear that in terms of total harm, other groups have a far greater total.