I took a course on irony. It's been described as an 'invincible' form of criticism. If irony comes in the form of a ridiculous juxtaposition, it is difficult to respond without making overt reference to it. This reference brings unwanted attention to the juxtaposition. The more entertaining/distracting the juxtaposition is, the more attention it will draw to itself at this point, weakening the argument being made against it.