Well, if I had to hazard a guess, this kind of cynical speech would come from a character like Mr. Bennet, who manages to perfectly combine cynicism with whimsical humour in what he says and does. Certainly such a saying perfectly reflects his character and the sarcastic enjoyment he takes in laughing at the faults of others. Consider the way that he responds to the arrival of Mr. Collins by thinking not of how tiresome his visit will be but only of the enjoyment that having such a thoroughly stupid man staying with him will afford him.
As for other characters, I do wonder whether somebody like Lady Catherine de Bourgh, in her complete arrogance, would say something like this but be blind to the irony of her own words. Considering her own disagreable nature, the fact that she would find it too much bother and effort to like somebody else would clearly show her character through such a statement.