Points of sail must be set as to the "true" wind direction on the course. To have any arbitrary points relative to the apparent wind on any particular craft at any particular time is just unworkable as the apparent wind is different on any given class of boat compared to any other class. As the apparent wind is a vector of the true wind speed combined with the speed of the class, and as at most times most boats are travelling at different speeds relative to each other at any given times (even on the same point of sail), each boat will register a different apparent wind direction at the same time. To try to use "apparent wind" would lead to anarchy on the race course.