Being popular gives us the "ism" part, by definition 3 at http://en.wiktionary.org/wiki/-ism :
"a tendency of behaviour, action or opinion belonging to a class or group of persons; the result of a doctrine, ideology, principle, or lack thereof"
The "absurd" part also fits pretty well: http://dictionary.cambridge.org/dictionary/british/absurd "stupid or unreasonable; silly in a humorous way"