I've never been a huge and unapologetic fan of genre literature, and I've always held a particular antipathy for some mysteries for the same reasons Lionel Twain does at the end of
Murder By Death, condemning detectives like Sam Diamond, Jessica Marbles and Dick and Dora Charleston:
You've tricked and fooled your readers for years. You've tortured us all with surprise endings that made no sense. You've introduced characters in the last five pages that were never in the book before! You've withheld clues and information that made it impossible for us to guess who did it. But now — the tables are turned. Millions of angry mystery readers are now getting their revenge. When the world learns I've outsmarted you, they'll be selling your $1.95 books for twelve cents.
Mysteries are often stupid. They're typically written backwards from a simple equation (
A + Killing B + Clue C = Getting Caught), and the text leading up to its mathematical execution tends to be choked with insultingly heavy misdirection and pages of indulgent imagery and banal musings on humanity. (The rose thorns meant their love could cause bloodshed? The shy witness was vulnerable?)

Genre literature, detective fiction included, tends to sacrifice (or fail to achieve) fuller characterizations either due to the needs of plot or the inability of authors to meet the ordinary needs of three-dimensional personalities in "literature." A more generous person likely thinks the formats and demands of genre stuff infringe on character portraits, and a cynic sees an author running off to genre because he hasn't the talent to make the real world interesting.
All too often the evidence points to the latter condition. For one thing, it's highly unlikely that a truly talented author would seek a genre in which his talents are held in abeyance; and, even if he did, it's less likely that he'd restrict his talents and not find a way to break them free. For another, in terms of detective fiction, all too often the evidence points to the author's disabilities and need for assistance. He creates that final equation and then prefaces it with hundreds of pages of fractured ideations of "what people are," exercising thoughtful-evocative muscles he simply lacks. Doubtless, to the author, this seems like heady stuff, but it takes only a few pages of Mrs. Padgett delighting in her peonies and Mrs. Addison sneering at her own maid to figure out who is a good person and who is a bad person and whether the author thinks humanity is better off in a bucolic and frugal setting instead of one of unreflective privilege.