According to the sentence you've quoted, Roth's original plan for the novel was extremely "dull and flat." In other words, he had a pretty terrible idea. The only thing he did that was "genius" was to NOT write the novel. The "quite" is ironic because it implies (as Jasmine has said) that he almost wrote the book, or came very close to writing the book -- but he couldn't "quite" bring himself to write it. The fact that he just barely managed to talk himself out of writing a really terrible book certainly doesn't make him a "genius." That's where the irony is coming from.

To me it sounds to be positive to Roth. I dont hear any irony in this sentence.. Not quite ready = not exactly ready. It is not saying its not ready at all, it is almost ready but just not 100% ready. He is quite impressive = he's is pretty impressive. You are not commiting 100% but saying he is fairly or somewhat impressive. You were surprised in a way, that he was impressive. It is a testiment to his genious that he couldnt exactly bring himself to write a dull book like the first one. He might have wanted to write the book but he couldn't 100% do it. He might have come close, he was thinking about it but he wasn't "quite" able to do so.

Hi, consider that *quite has at least two meanings in American-, rather than in British English. My dictionary says: -- in English it means "enough": I feel quite well ( > to do something) -- in American it means "very": I feel quite well // Also: Fairly, quite, rather and pretty, they all can be used to say "enough", whereas: - fairly means: not so much - quite means: a good quantity - rather also means: maybe too much - pretty is like *fairly and *quite, but it's mainly used in the spoken language