Fitzgerald squandering his talent - in Tender is the Night

I hate to continue in this vein, but F. Scott Fitzgerald's "Tender is the Night" continues to be incredibly annoying. There are many, many novels about horrible and worthless people who come to ruin through their own foolishness - but few as well-written as Tender is the Night. Just as I feel the characters in this novel are wasting their lives and squandering their talents (not that there's a shred of evidence that any of them are talented - it's just a posited fact from Fitzgerald that we have to accept if we're to buy into the novel at all), I have to say also that Fitzgerald - an incredibly hard and dedicated worker, despite his alcoholism, unlike the characters he's writing about - dis squander his talents on this novel. When you look at his best work - Gatsby, some of the stories, the late writing about Hollywood, which he loathed but well understood - you have to wonder why he spent 7 years on this work, though perhaps it will change course somewhat as Nicole heads toward her inevitably breakdown? I'm about a third of the way through, 100+ pages, and the main character, Dick Diver, has done nothing worthwhile. Section I just read last night he and Nicole travel from the Riviera to Paris with 17-year-old starlet, Rosemary (amazingly, her otherwise thoughtful and protective mother thinks this is a good idea) and, in Paris, allows her to get smashed on champagne, then enters her hotel room, where she flings herself on him and he, nobly, resists the temptation - at least for the moment - but what the hell is he doing? This so-called brilliant doctor/psychiatrist, Rhodes Scholar, and so forth, has done nothing to help a single person and has shown, at least as a character, not the slightest awareness of psychology or medicine or for that matter human feeling. Sorry to beat up on this novel so much, as (as noted above) it has some stunningly beautiful passages and phrases - which shows all the more clearly the ability that Fitzgerald wasted through misdirection.