Wonderful essay! Because of their candor many similar works will be banished to library stacks or discarded outright. (A professor once told his class to write like Kipling. I should have listened.) No survey of American detectives can omit the marvelous badinage of Nero Wolfe and Archie Goodwin, creations of Rex Stout certain to make you laugh aloud. But there is no self deception in the palaver, whether about communism in The Second Confession (1949) or romance in Some Buried Caesar (1939).
Do not neglect the British "cozy," either. Human motivation is foremost in Sayers' Murder Must Advertise (1953) and the learned spinsters in Gaudy Night (1935) are in their way frightening as any gumshoe. Allingham is supreme in this genre as is her dissection of the smart set in Dancers in Mourning and The Fashion in Shrouds (1937 and '38). Granted Christie's pinch penny style can be annoying but the ability to call a spade a spade and even more is still there even if race consciousness is taken for granted.