I don't disagree with the policy in general.

We have enough need here without importing extra need. I would love it if we as a country could afford to care for all regardless of their need; but the pragmatist in me says that is simply not the case. In the real world, I would prioritize the care of New Zealanders over those of people trying to move here.

the policy treats people with disabilities as cost burdens and is ableist

Is it wrong to treat a person who would in fact be a cost burden as if that person would be a cost burden? I don't think the answer is obviously "yes." A country owes equal treatment to its own citizens but generally speaking a country doesn't owe much to foreigners. It can be pragmatic when selecting immigrants in a way that it can't be when dealing with its own people.