Every day, at a significant expense of time and effort, George engages in activity E. We ask him whether he does E because he is morally required (whether absolutely or prima facie) to do so? He denies it. We ask him whether he does E because he desires to do E or desires something else which the doing of E promotes? He denies it. We suggest to George that perhaps he simply sees E or something promoted by E as good, whether instrumentally or not, and that's why he does it. George responds that whether E has value or not, that value is not why he engages in it. Finally, we query whether George does E because it is pleasant. George denies it, emphasizing that E is only sometimes pleasant.
Assuming George's answers are correct, and not merely a reflection of insufficient insight into himself, it seems that George is being irrational in engaging in E. In fact, we may even think that too many questions are given above since we may think more simply that if someone does something not for the sake of a good, then she is not acting rationally. (We may even go one step further and say that this situation is impossible, and hence the conditional is a per impossibile one.)
But now suppose that E is the activity of living one's doxastic life in accordance with epistemic norms. If the above judgments are right, then unless one does E out of moral duty, or for the sake of a good, or to fulfill a desire or for pleasure, then I act irrationally. But of course to engage in E is a paradigm of rationality, and to fail to engage in E is a paradigm of irrationality. It would not be plausible to explain the rationality of people in engaging in E by means of desire or pleasure. Whether it is rational to engage in epistemically rational practices does not depend on one's desires or pleasures, and one shouldn't engage in E merely out of desire or for pleasure.
So the appropriate reason for engaging in E is a moral duty or a good. Now I submit that genuine norms (as opposed to, say, the norms of SS officer practice) are reasons for acting on the norms. Thus, if epistemic norms are genuine norms, they are reasons for E. But the appropriate reason for E is moral duty or a good. Therefore, epistemic norms are moral duties or express goods.