I take your point—it is of course possible to use any musical element in a clichéd manner—but I'm not sure I take Palmer's. If one avoids, say, tritones in specifically musical contexts (by listening to non-dissonant music), and only encounters them in quasi-musical contexts (like monster-movie soundtracks), then yes, one might regard them as clichés; but I feel like the stock response is as much the problem as the stock usage. (Is the usage of Beethoven's 5th and 9th, and Barber's Adagio, and Carmina Burana in film soundtracks so clichéd filmmakers should stop using them? Well, maybe.)
Perhaps I'm overreading Palmer, but I think he is in fact saying something more than you think he's saying: that if Britten had used tritones, in a context where their musical effect was entirely warranted—i.e., The Turn of the Screw is, in fact, a kind of (very subtle) "monster movie"—the result would have been clichéd, and therefore less masterly than what actually resulted; but (never having heard it, I'm only guessing), that result seems to have been a kind of blandness, so that you (more conservative than I, but less than Palmer) found it uninteresting.
no subject
Perhaps I'm overreading Palmer, but I think he is in fact saying something more than you think he's saying: that if Britten had used tritones, in a context where their musical effect was entirely warranted—i.e., The Turn of the Screw is, in fact, a kind of (very subtle) "monster movie"—the result would have been clichéd, and therefore less masterly than what actually resulted; but (never having heard it, I'm only guessing), that result seems to have been a kind of blandness, so that you (more conservative than I, but less than Palmer) found it uninteresting.
Don Keller