When the committee gave out the prizes, the people in attendance numbers to see

Rural people are not as foolish as they may seem.

The first two nights of the king and duke's production tricked the rural people. They did not get the performance that they had hoped for. This third night, the people are all coming in with rotten items to throw at the duke and the king as a sign of their distaste for the show. The show is not worth the money so to say that they are difficult to please or lacking in taste is not correct, because even the king and the duke know that their show is just a prank to get more money. This works. Not only did they have everyone in the town show up to the show, the people also came back a second time just to throw things at them.