While Chandler’s stylistic flourishes and poses are contrived at points, the direct and lyrical quality of his prose is far above any pyrotechnics that a great storyteller like Robert Bloch could provide.
Calling Chandler a hack seems a bit much. James Hadley Chase was a hack. Mickey Spillane’s great hero, Carroll John Daly, was a hack. Chandler? I’ll agree to disagree.
Me, too, with respect to Chandler. Some of the books had problems, but nothing big enough to make you doubt the strengths were real. I’ll concede that he didn’t have a lot of help.
In fact, let’s posit this: that writers in this despised genre pretty much all look worse than they deserve, because they didn’t get the best, or even the second-best, reading and editing that publishing could provide. James Agee could write too, but I’ll bet 1941’s Let Us Now Praise Famous Men got a lot more TLC from Houghton-Mifflin than Hammett, Chandler, and for that matter Stout and MacDonald got in their whole careers. These are all good writers (actually, I don’t like Ross MacDonald much), but you have to award extra points for quarterbacking the B-team.
I did say “pretty much,” and here’s the payoff: Spillane excluded. Better editing would have made his novels disappear. His stock in trade was childishly-pornographic violence and sex, or, mostly, violence-as-sex. He was offering raw corn whiskey to the folks who thought aging and filters are for sissies, or at least felt that way once in a while. Spillane was a genius in the same way Larry Flint is: matching the perfect product to a certain widespread, yet widely unacknowledged taste, and that takes smarts. And imagination. And a typewriter. And brutality. But not literary merit, and I assert he deserves none.
I, too, find your characterization of Chandler odd, especially since his plots were only an excuse for his prose and characters. He was by far the greatest stylist of the genre, and if his style seems contrived today, it’s because so many people tried to follow him that it became cliche.
That’s Donald E. Westlake. You’re conflating his real name with the Richard Stark pseudonym he used when writing the Parker books. (You ain’t talking about physics now, punk; you’re in my world. 
)
Parker was a crook, not a detective. Westlake wrote very few books that could be called hardboiled detective yarns.
In fact, Chandler and Hammett are the only true hardboiled writers on this list. Several can be called noir, although I’d argue that Westlake was never a noir writer.
Does it make a difference? I think so. The line between detective fiction and crime fiction is inherently fuzzy, but get far enough from that line, as most of the writers you mention did most of the time, and the distinction makes itself clear.
The central character of a detective novel must be fit for Chandler’s “mean streets”. “But down these mean streets a man must go who is not himself mean, who is neither tarnished nor afraid.”
Spillane stretches that to the breaking point with his not merely tarnished but vile Hammer character. But Spillane believed seriously in Hammer. The more relevant quote in “The Simple Art of Murder” is the last line, “a world in which gangsters can rule nations and almost rule cities … it is not a fragrant world, but it is the world you live in.” Spillane’s anti-communism saw the Commies are gangsters who ruled nations and wanted to rule his. Combating them was a moral imperative, and he meant to emphasize how high the end stakes were by making the means as unpretty as possible. It was moral pornography, wish-fulfillment fantasy as I said in that other thread. Worked great. Spillane’s first five paperbacks were the bestselling paperbacks in history for many years after they were written.
Crime novels don’t have any such underpinnings; they can look into the heads of the criminals and that gives them greater power than detective novels, even the best. There’s an odd little book out by P. D. James, Talking About Detective Fiction, in which she tries very hard to give the formal detective story some weight, but keeps being forced to end arguments by saying that it’s only mindless entertainment. Over and over in every chapter. That’s probably why Hammett and Chandler wound up as drunks.
I also believe that Chandler was a better writer than Hammett. That argument goes round and round like the one between Hemingway and Fitzgerald and I could make a case either way and have come down on different sides at different times. Calling Chandler a mere “competent hack” is a literary felony, though. That’s on the level of the guy in the current thread who insists that the Bee Gees are better than The Beatles.
I know that noir movies could feature either detectives or crooks, but the print world was more divided. Noir as a genre faded by the mid-1950s. It couldn’t survive the harsh light of prosperity. Crime and depravity and grittiness are timeless, but we approach them distinctively with each era.
I just finished rereading Poodle Springs. It is the eighth Philip Marlowe novel. Raymond Chandler was working on it when he died in 1959.
Robert B. Parker was asked by the estate to finish it in the early 80’s. He did a remarkable job capturing Chandler’s voice. Great edition to the Marlowe series.