First, and most obvious, is the fact that most operas are in other languages than English. The translation blinds us to whatever faults, or virtues, the original libretto might have once had. Once translated and put up on surtitles, all opera libretti become equally stilted and awkward. Sometimes the effect is bathetic, as in a production I once say of Debussy's Pelleas et Melisande: "I am not happy," sobs Melisande, who has just been verbally abused by her husband for losing her wedding ring. Being a regular operagoer, however, requires you to get over this awkwardness of expression. You learn to separate the music of the opera from the texts; the former is of high quality and high importance, while the latter is a mere aid to help you comprehend the action. To sum up: since the advent of surtitles, opera audiences have been trained to expect opera texts to be poorly written, and to compensate for this.
Writing as Samuel Marchbanks, Robertson Davies inveighed against the low literary quality of the translated texts at art-song recitals, and tried to imagine how an English song like "Drink to me only with thine eyes" would be translated for an Italian-speaking audience:
Let us agree, when drinking, to employ the eyeballs only; similarly with kisses. I sent you some flowers recently, and you sent them back after breathing on them; they are still alive but are now imbued with your own personal odour.A second, related point is that an alarming number of composers have a tin ear for poetry. Here's an example from the "In taberna" movement of Carmina Burana:
Parum sexcente nummateIf you know the work, you'll remember that this comes close to the end of the movement; each line ending is punctuated by a short, snappy orchestral interlude with lots of percussion. Musically, it's very exciting, but in terms of Latin text setting, it's terrible - Orff steamrolls through each line, without care for the terrified punctuation marks that lie in his path, and then adds huge breaks at each line ending despite the fact that the sense of the text continues onwards.
durant, cum immoderate
bibunt omnes sine meta.
Few of six hundred coins
last, with immoderation
drinks everyone without limit.
I chose a Latin example because it's supposed to be an easy language to set well - but Orff absolutely destroys any logical sense the text might originally have had. A persistent myth still exists in the musical world that English is extraordinarily difficult to set well, but it's not, and as Exhibit A I offer you the entire corpus of English cathedral music. Whatever you may think about the music of Stanford, Howells, etc., I would argue that an essential characteristic of their music is this exacting care in text setting, inherited from the Tudor polyphonists. Every accented syllable is in its appropriate place, every comma is observed, and the sense of the text is carefully matched to the musical form. And so, when Benjamin Britten came to writing operas, he didn't have far to look for models of English text setting. Which is why it annoyed me so much to read John Adams's disparaging comments about Britten's "stilted" text setting - it's Adams, with his subjugation of textual sense to the needs of postminimalist process, whose text setting is mannered.
The appallingly low standard of vocal text setting in contemporary music is one of my continual hobbyhorses, and so I fear that I've gotten far away from my original point, which is simply this: composers frequently butcher the texts they try to set. When punctuation marks are ignored, accented syllables are not placed in appropriate places in the bar, and the text is generally rendered unintelligible both from a phonetic and semantic perspective, we get out of the habit of listening to the text at all.
The upshot of all of this, unfortunately, is that attending vocal performances trains listeners to scan the text for general sense but not to try to follow it or to judge its literary quality. If we don't understand the language being set, we have to follow an awkward and often bathetic translation; if we do understand the language, the text setting often makes it impossible for us to follow. So why is it surprising that millions of listeners saw nothing unusual in an opera with a poorly-written libretto? And who better than Ron Rosenbaum, an outsider to the opera scene, to point out the problem?