Besides the fact that symmetrical wings fly the same inverted as upright are there any other reasons why aerobatic planes prefer symmetrical wings? Can symmetrical wings achieve a higher critical angle of attack? Does the large ailerons on aerobatic aircraft have anything to do with it?
One goal for most aerobatic planes is neutral pitch stability, which eliminates any pitch response related to air speed, which allows for clean straight lines during dives or climbs without requiring elevator adjustment for speed.
Cambered airfoils produce a pitch down torque which increases with speed, and this would interfere with the goal of neutral pitch stability. This would be another reason for using symmetrical airfoils on aerobatic aircraft.