Why do people try to dismiss things they don't like as "hilarious" when they have no cogent argument against them?

Anyone ever notice how when people don’t like a point of view, but don’t actually have a cogent case against it, they make a last-ditched attempt to belittle the argument by dismissing it as “hilarious”? And occasionally employ hyperbole to drive the point home? Examples abound on Fluther and other crowdsourced commenting sites on the Internet. Is it caused by people experiencing cognitive dissonance upon hearing information that contradicts their view of how reality should be, but lacking the critical thinking skills, vocabulary, wit, and/or grasp on reality to make a cogent counterpoint? This is especially seen in political discourse.