Why were farmers laughed at by Song people when they were waiting for him?

Because farmers want to get something for nothing.

Because he was lucky enough to get a rabbit that hit a stump and died, he thought that another rabbit would also hit the stump and die, so he put down his furniture and stopped farming. The result must be that the rabbit didn't get it and the field was abandoned. His idea of hoping for luck and getting something for nothing is stupid and ridiculous.

"Waiting for the Rabbit" tells us that we should look at things from a changing point of view, and we should not stick to dogma or stay the same.