I did not play Call of Cthulhu, back in the day. I knew it, though, and greatly respected both its game system (the likable Basic) and its setting. Recently, I have noticed people who lament that CoC was not very keen (or very effective, at that) at recreating Lovecraftian cosmic horror, and typically resulted in more action-oriented pulp fiction. The rule system itself was not explicitly tailored for the purpose (it was a solid, generic skill-based system). This is closely parallel to MERP with respect to Tolkien: Rolemaster (Spell Law especially) did not suit particularly well the source material, and the adventures (while very well documented) had a distinctly sandboxy, wilderness adventuring feeling.
The moral? Maybe I should not say so, being as fond as I am of “genre”, but the fact is that it is not by any means obvious that everything that works in fiction should work in roleplaying. So maybe one should content himself with having RPGs that participate to some extent in the atmosphere of his favourite fiction, and enjoy games in and for themselves. It is a fact that some of the most iconic and influential tropes of RPGs were not inspired by any specific genre of fiction (at least, not directly and recognizably). It is the case with much of what we call “classic fantasy”. It is D&D that made today’s fantasy genre, not vice versa. And this is also why D&D still retains its appeal, even to people that could not care less about Old School Renaissance: D&D is attractive because it is its own thing, it made the rules rather than following them. So who cares if the game system does not make much sense? Same with the World of Darkness: it did not try and recreate one specific genre or the other, but it invented a new blend of dark fantasy/horror/mysticism which is uniquely its own (and largely sucks, IMHO: more on this in future posts).