I am curious about the purpose of the "Heroic" and "Villainous" keywords. From a game balance perspective, I'm wondering what can be said about these keywords, in relation to their use in preventing the play of both Heroic and Villainous characters simultaneously, especially with the existence of Tyler Scindere. Is there something that makes the use of both, rather than one or the other, somehow overpowered, and if so, does this not become less of an issue as more and more of each are added to the game?
The reason I ask comes from more of a thematic outlook on the game, specifically the "why" of Heroic and Villainous keywords appearing in a setting whose primary distinction is the objective absence of a good-evil dichotomy. Lovecraft himself was once quoted as saying, "Now all my tales are based on the fundamental premise that common human laws and interests have no validity or significance in the vast cosmos-at-large." The Old Ones, for example, are seen by the investigators as malevolent entities for the threat they pose to mankind, but by and large they have no care or concern whatsoever for our survival or extinction. We simply have no relevance in this greater cosmic battle that is unfolding.
So to sum up, I guess what I'm asking is, should there be no game-breaking factor at present (for if there is, my entire argument more or less breaks down), why do we want or need these keywords in Call of Cthulhu?