Probably the most common question in applied statistics is "Does X affect Y?" To answer this, you get data and do some analysis that, from the bayesian perspective, leads you to some distribution of beliefs over how X affects Y. From a non-bayesian perspective you still have some kind of uncertainty. But you still want to turn that into a yes/no, so you come up with a rule for turning that uncertainty into a deterministic yes/no. Data in, yes or no out.