Finished this book today. The prose style and the dialogues are definitely very strong. Marlowe is hilariously savage and made me laugh more than I feel comfortable to admit.
But the characters are bland, not because they are all either “hoodlums” or too depressed, but because their actions aren’t very well-motivated. Among the many examples that I’m too lazy to type out, the most irritating one is why >!Terry Lennox had to flee to Mexico when it wasn’t him who killed his wife (the police only went after him because his departure created the impression that he absconded)!<. The cynicisms of some characters such as Harlan Potter and Marlowe himself are puzzling without sufficient backstory support. The plot is also somewhat far-fetched and nonsensical, with a corny >!fake suicide!< as the book’s ending.
So why do people love this book? I even saw someone claim that The Long Goodbye is one of the best books written in the English language. What am I missing?
I’ll say at the outset that I read this book recently and could admire it without loving it, but I believe the answer to your question – what you’re missing – is the importance of the book as social critique (in particular, societal corruption as an inevitable component of American life) and an exemplar of the hardboiled style/sensibility. It seems clear that he was using some of the convention of the crime novel, but he elevates prose (he is a superb stylist) and characterization over plot.
Reading it in expectation of a dated by cracking good crime novel doesn’t work. Its importance lies elsewhere.
Not sure if that helps you come to terms with it, of course. Your mileage will vary! :)