Food poisoning from juice and milk? Mankind lived for thousands of years without refrigeration and still enjoyed milk and juice. A functioning refrigerator will do just fine.
Truth be told, Americans will always be the primary passengers on ANY Carnival cruise. My last Carnival cruise was in Europe and it was still mainly Americans. Carnival doesn't attract a large number of non-Americans.
Who is "we?" Whatever people pick up on the ship, they will bring back home. That could be an issue.
Cruising is a non-necessary, BS activity. It's optional. I'd rather have no cruises than have the attitude of "virus, who cares?"