So he only read 1.5 books of Dostoevsky, and now he telling everyone to read his books. I get it, I also had a religious experience when I read Crime and Punishment, but one cannot assume all his books will be that great without actually reading more of them. Call me back when you get through a few more. Or maybe change the title to "Why read Crime And Punishment".
There are many writers who have only one great book, and the others are all flops. Dosteovsky had a few that were utter flops in the literary sense. (The Idiot did not sell well, although it has its merits). You could even say he only hit his stride when he wrote Brothers.
John Kennedy Toole's "Confederacy of Dunces" was not only brilliantly comedic, but also quit profound. His other works were nothing special.