Were judged by are actions and what we did in life. Dieing does not make you a better person.
From my understanding, it's more of a tradition, or a rule of thumb, than a capital offense.
Kind of a way of saying well: that's that.
I don't think you're supposed to white wash assholes, just don't marinate in it now that it's less important.
Of course, you don't denigrate yourself or others for the dead, but carrying their water would be real dumb too.