Attendance has nothing to do with it. The Gulf Cup is not a Micky Mouse Cup. It is the second strongest competition in Asia after the Asian Cup itself. Don't give me other bullshit of some Iranian, Turkmenistan, Afghanistan cup something being stronger.
The reason for higher attendances is because it is often held in neighboring countries where GCC citizens can travel freely to other GCC member states.
It is much more difficult when the Asian Cup is held in Indonesia 10.000 km away or Japan for fans of Arab countries to attend those games.
Your comment makes no sense like your first one.
The history of KSA in the Asian Cup speaks for itself. It is always the priority and the most prestigious Asian tournament.