The issue is that as far as I can see, none of the major English-speaking sailing nations are assured of being able to hold a valid regatta under this policy. All of them have policies under which athletes from some countries may receive discriminatory treatment, and sailing as a sport is not going to be able to change those policies.
Here in Oz I think we still maintain a confidential list of nations whose citizens have a statistically high chance of overstaying their visas. Athletes from such countries can be denied visas because it is considered that there is too high a risk that they will overstay, even when athletes in identical circumstances but from low-risk countries are granted their visas.
Canada did the same thing just last year;
http://ottawacitizen.com/news/local-news/canada-blocks-ugandan-kayakers-from-ottawa-river-world-championship" rel="nofollow - http://ottawacitizen.com/news/local-news/canada-blocks-ugandan-kayakers-from-ottawa-river-world-championship
The UK has refused visas to athletes from a particular country as recently as three months ago;
http://%20timesofindia.indiatimes.com/sports/boxing/Britain-risks-forfeiting-boxing-clash-after-Moroccan-visas-refused/articleshow/51446934.cms" rel="nofollow - http:// timesofindia.indiatimes.com/sports/boxing/Britain-risks-forfeiting-boxing-clash-after-Moroccan-visas-refused/articleshow/51446934.cms
The same thing occurs in the USA, where apparently professionals from Cuba are not allowed to compete;
http://athletesvisa.blogspot.com.au/2014/12/normalization-of-relations-with-cuba.html" rel="nofollow - http://athletesvisa.blogspot.com.au/2014/12/normalization-of-relations-with-cuba.html
I'm not sure how NZ can actually fulfil ISAF's new requirements. They have a list of certain countries from which athletes will (according to the Immigration Dept website) be automatically granted a visa. Athletes from other countries must apply. One would assume that the application process will bring a chance of refusal, therefore there is unequal treatment.
Such decisions don't have to be political - Samoa denied entry to athletes from one nations because of fears of the Ebola virus. Canada, Australia and other countries instituted wider restrictions on people from certain countries because of the Ebola virus. So what happens if someone similar occurs again in the lead up to a worlds in the UK, USA or similar Western nation?
I'm NOT defending the actions of Malaysia in regard to the last Youth Worlds. Malaysia is a country that operates under racist laws even when dealing with its own citizens. But how did ISAF (whoops, World Sailing) adopt a position that will apparently prevent future major titles in some of the sport's core countries, including the top two Olympic sailing nations?
Frankly one wonders if the new policy may not have been a poorly-researched knee jerk reaction brought in after pressure from people in the sport who didn't do their own research. And luckily (from some angles) not many people from the affected countries do world sailing titles. But for how long can we just keep on hoping that no one from (say) Uganda or Cuba will enter an ISAF event in Australia, the USA, Canada or the UK? And in what country in the world can the ISAF policy apply?