I recommend people read Don's full speech (credit to Russell who links to it). It is very pro-immigration, but anti some of the current policies. And yes you can be one and not the other. Those arguing that are often the same who argued Don was a racist for his Orewa speech.
The NZ Herald editorial has labelled National's policy as rational and am improvement on Labour's knee-jerk reactions and piecemeal change. It does not agree with every aspect but overall is positive.