I knew that Paul Tillich anticipated some of the recent expressions of dissatisfaction with pervasive irony (inspired by David Foster Wallace's critique [pdf]). I finally found the quote. Here it is:
"The word ‘irony’ means that the infinite is superior to any finite concretion and drives beyond to another finite concretion. The ego of the romantic in Schlegel’s sense is free from bondage to the concrete situation. … Romanticism drives beyond any particular actualization of the infinite in a finite situation. Now this romantic irony breaks through the sociological forms, for instance, … the idea of the family, … the political stability, etc. All these forms now become questionable. … [Irony] always says ‘no’ as well to a concrete solution to life’s problems. … But if this happens, then with the loss of concreteness a sense of emptiness sets in. Schlegel had the feeling that by undercutting the forms of life, the beliefs, the ethical ties to family, etc., a situation arises in which there is no content, no obligatory contents. This results in a feeling of emptiness with respect to the meaning of life. … It is this dissatisfaction with any concrete situation, this ironical undercutting of everything, not in terms of a direct revolutionary attack, and not in order to transform reality …, but in terms of questioning, undercutting, etc. …" -- Paul Tillich (History of Christian Thought, pp. 385-6)
Update: Tillich must have been influenced by Kierkegaard's critique of pure irony. Here are some relevant passages (with citations at end of post):
'In irony, however, since everything is shown to be vanity, the subject becomes free. The more vain everything becomes, all the lighter, emptier, and volatilized the subject becomes.' (pp. 258-8)
'[Pure] irony is no longer directed against this or that particular phenomenon, against a particular existing thing, but … the whole of existence has become alien to the ironic subject and the ironic subject in turn alien to existence, that as actuality has lost its validity for the ironic subject, he himself has to a certain degree become unactual.' (p. 259)
'In order for the acting individual to be able to accomplish his task by fulfilling actuality, he must feel himself integrated in a larger context, must feel the earnestness of responsibility, must feel and respect every reasonable consequence. Irony is free from this. It knows it has the power to start all over again if it so pleases; anything that happened before is not binding.' (p. 279)
'Boredom is the only continuity the ironist has.' (p. 285)
All quotes are from Kierkegaard’s The Concept of Irony, with continual reference to Socrates (ed. and trans. H. V. Hong and E. H. Hong [Princeton University Press, 1989]); quotes are taken from Brad Frazier, ‘Kierkegaard on the Problems of Pure Irony’ Journal of Religious Ethics, 32 (2004): 417-47.