I think "infamous" is the right word for the poems. Christabel LaMotte's were bloody awful (IMO). I quite liked Ash's though. Is that a symptom of being male?

About interpretation: I don't think the poems are meant to be there as poems, for you to interpret as you wish in their own right. They're devices, ersatz poems, contrived for the sake of the novel they're in. They are the way they are (trite, pretentious, or whatever) because their being that way serves the purposes of the novel. Such flaws as they have are deliberate. I can see why this is frustrating for a poetry lover – they're like a cardboard cut-out of a sex symbol instead of the real thing – but you've got to hand it to Byatt that writing poetry that's bad in exactly the way you want it to be shows incredible skill. It's like a virtuoso trying to sing off-key on purpose – so much more difficult than doing it well.