I think a stumbling block for the majority is the actual distribution of the competition surcharge.
As has been said many entrants realise that they will win nothing and will opt to shoot the targets at a cheaper cost.
Now, If the prize fund is only going to be won by maybe ten expert shots classified in AA the vast majority in B & A class will be disillusioned as they are actually swelling the pot and have no chance , or very little of a return.
By the same token if the A or B class only prize fund was vast then the AA shot who had honed their skills would be disadvantaged.
Why should a High Gun from AA have £200 prize and his mate have £100 for winning A class? Because they are good, but it is hardly fair when the B class have provided the majority of prize cash but the winner can only win £100 maximum.
Maybe if a formula could be used where the classes that provide the higher percentage of the pot could be paid back in more places that may be an incentive to enter competition.