As a sailor, I would want my class to be ISAF sanctioned for two reasons.

Class rules are stable world wide and changes must go through ISAF through the approved "class rule change mechanism". This assures me that the crazy XXX's can't willy nilly change the boat weight and still call it " F16 class"

If they did .... ISAF is the organization that would tell US Sailing to tell the host yacht club... that hosting the F16 illegal class would cause them to loose their standing within the national sailing community. Sailors who participate in the event would also be barred from competing in other ISAF sanctioned events. ISAF hammers both clubs and sailors for rules violations. (See also drug testing rule, professional sailor rules etc etc)

Major championships (worlds, continentals) must be announced according to a specific calander, They must have a certain level of international participation (for a worlds)_.... the event must have a certain level of international judges and PRO with a certain level of skill. You could not for instance declare the upcoming gulfport regatta... the US Nationals just because it looked like it would be well attended. (those Californan's would have a legit beef that they were not given notice about the Nationals, etc etc.)

In short, ISAF standing gives your organization the stamp of approval that you meet a level of organization and excellence equivalent to the other International classes.

As a sailor... I would have a certain level of confidence in what to expect of an ISAF sanctioned class.

If memory serves... Wouter and the class founders had an extensive debate on the merits of getting ISAF recognition. They had gotten boats and races in the required regions etc etc. It cost a good bit of money to press on with the application and the founders did not pursue it.

Your opinion might vary as to the benefits of ISAF recognition.

In the end... it's the class.... (the organizational structure, rules, and demonstrated leadership) that must have credibilty for consumers to buy into your organization as the racing class of F16's. It is this organizaton that makes sure the builders comply with the class rules and that the equipment is within tolerance and the racing fair around the world. ISAF is one way of getting this credibility.