Koster posted an interesting blog the other day called "Games as propoganda, games as statement" (http://www.raphkoster.com/2006/09/18/games-as-propaganda-games-as-statement/#comments). I'd like to add two further thoughts to that conversation:
First, while my own preference is usually for universal accessibility of stories (verbal or non), I believe it's foolish to fear making one's design lean noticeably toward a particular conclusion (propoganda). Designers often consider niche appeal only in terms of "I'm closing the door on these potential parties", but we should also consider the increased degree of appeal among those potential parties already included.
In other words, a universal story might attract both my interest and the interest of my antagonist, but not enough for either of us to purchase it (0 sales); while a story biased to my liking might have a stronger attraction for me (1 sale). So a niche story may occasionally have as much marketing advantage, ultimately, as a univeral one (a roughly equal number of people purchase the product).
Second, other media do involve some level of interaction comparable to games: the audience empathizes with the protagonists (and sometimes even the antagonists), often subconsciously bending the characters to its own interpretive preferences. For that and other reasons, even stories which are thematically antagonistic to the audience can sometimes win them over.
For one example, Bram Stoker's "Dracula" appeals not only to audiences who relish in gothic decadence, but also to those who perceive the character as a truly detestable being rightfully conquered. The novel's many assaults on Dracula's character and his ultimate defeat do not prevent many readers from imagining Dracula the hero and loving the story; and the plethora of perverse imagery does not prevent many readers from appreciating the novel's didactic value.