Well beside representing corruption and greedy people, wouldn't be surprised if they also have a position similar to generic harem protagonists. Where the generic protag serves as a everyguy placeholder, the ugly bastard could be sort of a more negative placeholder. Kind of an embodiment of negative feelings that some people feel about themselves and their place in the world. A placeholder of those who feel unwanted and who would like to lash out against those in a better position in life, something they couldn't get away with in real life. He doesn't represent how they really appear, but how they feel they appear.
I am probably an outlier here but in my case it's seeing decades-old arguments over a series and people getting extremely and viciously heated over what guy the main girl should go with, and the Ugly Bastard is the equivalent threat of "if you don't behave yourselves and stop fighting I am taking this car over the side of the bridge"
