The folk song "Cut Tan" satirizes corrupt officials. When they were in power, they were insatiable, shameless and benefited from no merit. Those who can be officials are not good people. (Being an official is being an official; "Gentleman" describes a good man with noble moral character and cultivation.
note:
This sentence is a traditional understanding of the folk song "Cut Tan" since ancient times, but in fact this understanding is wrong, and there is another way to understand it. If the subjects are interested, they can ask another question.