I love me a good whodunnit. Dashiell Hammet's books. The movie L.A. Confidential, heck, even the semi-spoof of whodunnits, Kiss Kiss Bang Bang. There's something about that pulp noir world and trying to discover who the bad guys are that is undeniably exciting.
I'd imagine you'd need to be super, duper smart to write an amazing whodunnit. There are red herrings to keep track of. Different characters going after the same thing differently. You have to maintain an element of surprise and give enough information to keep the reader interested. It's a brilliant balancing act that requires you to be more intelligent than each and every one of your audience members.
This oftentimes yields bizarre stories with even more bizarre conclusions. But if there's one thing that human beings prove time and again, is that every so often we trump fiction with our created realities. Like this story of a murder mystery that was solved all because of a bowl of soup.