Lol, apologies if I missed your mass immigration point - yes, mass migration into a fucked system can cause problems.
But my point still stands, this is due to bad long term planning and investment.
I don't think different cultures are the problem? It's the effect of those migrants on underfunded public services and housing supply and esp in NZ - wage growth that can cause friction.
Not forgetting that mass immigration is often driven to satisfy the business community to meet, often imaginary, labour shortages and suppress wage inflation.