I don’t think that there is any way that can be made to work with the modern sensibilities of the usual suspects. It’s funny, it used to be that some people actually enjoyed roleplaying as an evil character (and everyone else enjoyed fighting them), but as all of the ‘talk’ has become more and more about promoting ‘moral grey’ the more people expect everyone to have the character of an ingénue or a maiden aunt.
I think people still enjoy playing as evil characters (as well as shady ones). At the same time I prefer "moral grey", as you put it, because opponents that are purely evil (like, stupid evil) tend to be boring compared to someone who has interesting motivations behind his morally questionable actions.
That's why I enjoyed Denethor from Lords of the Rings (the book trilogy, not the movies) - he is an intelligent and noble character who gets corrupted by the manipulations of evil. Or "The Enemy Within" - this is a book in Warhammer Dark Fantasy setting written by Richard Lee Byers, a guy who has a master's degree in Psychology and it shows, because the book pretty damn good in what it tries to do. There is the obvious evil (the forces of Chaos, cultists, etc.), but the initial motivation of the protagonist is to save his own skin by working for the Witch Hunters. After that it gets worse, but the pace is such that both the protagonist and the reader are not noticing how the corruption starts taking its toil. And when the realization comes you're so deep that you might as well follow through on this, because the alternative is worse (and quite ironic, which is another thing I like about the story).