There are many outstanding mystery writers whose books have transcended the mundane to create great reading experiences. Their books are vehicles you can count on to deliver a good read every time. That is until the very end. Probably no one dares tell a great writer that their time is past.
One of the greatest examples of great plotting was Agatha Christie, whose last book "Elephants Can Remember" was just ghastly. Luckily she had some books saved that came out after her death that were skillfully plotted. Christie was great, but it was her fantastic plots, not the depths of her insight that we treasured.
Two men, both with PhD's, were the best mystery writers of the last 50 years. Ross McDonald was someone who made comments about society that were fascinating. One of his great lines went, "I sat down in the Harvard chair and it expelled me." You could see real people dealing with extraordinary problems in his novels. His last novel was really bad and upon his death we learned he had Alzheimer's.
The other guy, who had once been a professor at Northeastern, was Robert Parker. I got to know him because I was assistant to the president at Occidental College. We had this fabulous mystery collection that never had any PR. I was talking to Parker about having him host an event celebrating the collection. He he was a fabulous guy. One day I met him in Pasadena where he was signing his newest book. A raconteur he was a tremendous conversationalist. While we sat there and he signed books he finished off a sixpack of premium beer he'd brought with him. The event at Occidental never happened because the college president (whose dissertation was an annotated bibliography of someone I'd never heard of) didn't want to spend the money. I was never to see Parker again, but I cherished the time I spent with him.
When he started writing the Jesse Stone novels, you could see Jesse struggling with alcohol. Jesse didn't want to stop but the amount he drank scared him. I think Jesse was Parker. Parker died of a heart attack, but his last novel was terrible. His character, Spenser, used logic that made no sense and I made sure I didn't buy another Parker novel, remembering Ross McDonald. Shortly thereafter Parker died. But up until that last book, I was never disappointed. He was truly the King of crime fiction, and a great human being.