I can see why NCL sticks to their gun, notes can easily be forged...cut and paste the Dr's Office logo, and there you go, a nice official looking Dr's note.
As others have said, folks sharing these packages illegally are what caused NCL to make rules like they have done.
$40 a day isn't really all that much...buying by the drink adds up. If you're sure your husband won't reach that, cancel the both of y'all...