The problem with "gamifying" work is well-known to anyone who actually studies human motivation. Any exercise of control, and especially anything that makes people focus on their performance rather than the actual task they are doing, is bound to decrease motivation and quality. When kids worry about the test and their grade, they learn less. When professional athletes start worrying about the score instead of trusting their bodies, they do worse. This is a pretty basic feature of human psychology, but for some silly reason we think we can outwit it if we make our methods of control "fun" enough.