Well, the very thing about the exhortatory (sp?) mode is that it tells you that some kinds of behavior are admirable and others shameful -- not what's practical.

This site is not particularly fond of exhorting people to behave any one way, except to behave rationally. I suspect that is not because LW readers have no beliefs about what admirable behavior includes; I suspect there is even some overlap in their beliefs. I think it's more likely that they already take their own values for granted and are no longer looking to be preached at.