The thrust of his argument as I read it is that however faithfully a filmmaker tries to replicate a novel, a film can never be a true substitute:
'A good film requires careful attention, just as does a good novel, but the kind of attention being paid is not the kind required by fiction'and the two forms inevitably produce different creatures.
However it seems that now the adapters aren't even trying for replication. I have to admit I found interesting Andrew Davies's highlighting of the suppressed homosexual theme in A Room With a View (last Sunday night's adaptation) - but surely that suppression is part of the essence of the novel, a novel about suppression with its own meta-suppression. And as for the reversal of the novel's ending with the WWI addition, well please tell me why this was necessary. And another thing: the way these contemporary interpreters of Victorian and Edwardian middle-class female protagonists leave their mouths hanging OPEN! Is no one in the media old enough, or well enough (or sensitively enough) read to know that even in the early sixties girls were constantly expected to hold their mouths closed as a sign of breeding and virtue? And especially when it comes to Miss Lucy Honeychurch! Oh, I know that Lucy's got a wild soul, but remember it's a wild soul in conflict with her breeding, and it's her PIANO PLAYING which betrays this, not hanging lips and glittering teeth on show. Did they feel they had to 'modernise' her to make modern audiences identify? Or do they just not care?
All of this works towards a dilution of Lucy's suppression and eventual rebellion: not only would that piano playing be so much more shocking coming from a girl with all the historically-correct physical social manners, and her rebellion that much more dynamic (even - or especially - to modern eyes), but the explicitness of the homosexuality in the film dilutes the theme of Lucy's suppression which in the novel has to stand for it as well as for itself.
I'm telling you, Lucy's mouth wasn't the only one hanging open.