NZ is not so fortunate when it comes to keeping educated citizens (not just Pilots).
As a country NZ 'invests' a lot in educating their citizens across a broad range of disciplines only to lose a sizeable number to Australia and elsewhere.
NZ also seems to have a culture of not giving newcomers a chance to start a career. Many companies in NZ seem to only want staff with prior experience (i.e. - not invest in training new staff).