Monseigneur represents the excesses of the French aristocracy before the revolution. One telling scene is in chapter VII, when he drinks his morning chocolate. It took four men to provide him a simple cup of hot chocolate:

One lacquey carried the chocolate-pot into the sacred presence; a second, milled and frothed the chocolate with the little instrument he bore for that function; a third, presented the favoured napkin; a fourth (he of the two gold watches), poured the chocolate out....Deep would have been the blot upon his escutcheon if his chocolate had been ignobly waited on by only three men; he must have died of two.

Later on in the novel, he runs down a child and thinks a gold coin is enough to compensate the dead child's father. It was this sort of behavior that brought on the French Revolution, and by poking fun at the aristocracy in this way, Dickens is letting the reader know whose side he is on. 

By the way, Monseigneur means "my lord" in English, so everyone who says the man's name is bowing down to him in a sense. I think we could say Dickens did not want us to like him.