Retractions can be good things, since even scientists often fail to acknowledge their mistakes, preferring instead to allow erroneous findings simply to wither away in the back alleys of unreproducible literature. But they don’t surprise those of us who are familiar with how science works; we’re surprised only that retractions aren’t even more frequent.
Remember that study showing vaccines were linked to autism? The time scientists claimed to have cloned human embryonic stem cells? Or that simple, easy way that was supposed to revolutionize the creation of such stem cells?