There may be three reasons for this: First, the crews have discovered, even more as they continue to race, how difficult these boats are to sail when they are pushed beyond their previous limits. Second, any changes have to be agreed between the two teams and Murray plus the changes would have to be ratified by the Coast Guard and with a new marine permit.
Third, and perhaps most importantly for New Zealand fans, the Kiwis have changed and modified their boat and their racing so much that the old byword that Team NZ are better the harder it blows is not necessarily correct any more.
Oracle Team USA were also supposed to have set up their boat for the light September airs. But the evidence of our own eyes says otherwise. In Races 4 and Race 8 (both won by Oracle), the wind was at its strongest during the Cup match. Oracle seem faster in winds at that end of the scale.
In contrast, Team NZ's "sweet spot" seems to have somewhere in the region of 16-20 knots. There doesn't seem to be much difference between 16-20 knots and 21-23 knots but, in these sensitive and highly-strung boats...there is if they are not set up right for the conditions.
In addition, race management doesn't just blow the whistle if the wind gusts over the limit occasionally. They take a 5-minute rolling average and only then halt the racing, as happened yesterday.
So if the racing is called off for excess winds, don't see red - it might actually be better for black.