James Salter's Light Years: Great Writing Squandered?

About halfway through James Salter's 1975 novel, "Light Years," and am distressed at what seems to me to be a great talent misdirected (at least for this novel - I have really admired some of his other writing, especially the late stories): On the one hand, Salter gives us some beautiful writing and beautiful scenes: skating on the frozen Hudson, with a little girl ill with cancer being dragged along on a saucer by her dad; description of industrial Altoona, where daughter sits by hospital bedside of her dying dad and we understand why she left this town; surprisingly beautiful scenes of domestic tranquility: in the surf on Long Island, gathering for an Easter holiday; many long well-oiled dinners among friends; even a few very passionate sex scenes. All this toward what end, though? The central people in this novel, Viri and Nedra, are empty, vacant, a privileged couple with beautiful daughters (much remarked upon constantly) who cheat on each other and who both - particularly Nedra - feel they want something more out of life, something undefined: Oh, let's go to Paris, let's go to Italy, let's drive to the city and spend money. They remind me, to a degree, of the Diver family in Tender Is the Night - wealthy, intelligent, and frivolous - but at least in Tender events happen to move the plot along, whereas Light Years is a series of scenes, snapshots, moments that don't lead to any developments or changes in the characters - just accumulating evidence that they don't appreciate what they have and they don't know where they're going. Maybe novel will take shape in second half, and maybe some see this as a beautiful portrait of a a broken marriage but I'm thinking it's some great writing squandered.