Non-Awning pitches - why not cheaper ?

How many times have you booked a standard pitch with awning , turned up and found that the smallest one is left with the largest being occupied by a VW motorhome or small 2 berth van . ...so nowhere to pich your full awning ....( Rowntree Park was classic for this ..).cannot blame people for wanting space and doing this ..but is it worth actually incentivising non-awning / smaller pitches with a lower pitch fee ?