I think there are still legitimate grievances personally - Maori are more likely to be in jail, more likely to be unemployed, more likely to have drug and alcohol dependancy, they live for a shorter time (between 7 and 10 years) and have poorer health. That's without even going into the land/fisheries/foreshore claim issues. Many of their problems though are in essence problems of class nto race though, so they are not unique to the Maori experience.
The more worrying trend is that the NZ govt, which has long been too much in thrall to the security services, is using the flimsy pretext of islamist terror to deliver a good smacking to the people that they don't like. Ite may not be the most appealing character, but the consequences for social cohesion etc can't be goo din the long term.