Many of the CS games here allow the player to choose which stats to boost and which to neglect, such as Choice of the Dragon and the CoG games in general. But there are also CS games that already have a set protagonist, usually under the Hosted Games label. I think it depends on whether the story the author wishes to tell can only work with a set protagonist or can work with a wide variety of protagonists.
That said, interactive fiction, at least in this forum and the affiliated companies, is mostly about the player’s choices controlling the story. So, if you wished to create a game that had a very set storyline and the player could only use a character with a specific skillset, personality, and cannot control how the character responds to situations, it might as well be a traditional novel. If the purpose of a game is simply to guide the PC through something they have no choice over and the player cannot decide anything, I think it shouldn’t be grouped under “interactive.”
The author still has power over what choices they offer to the player, but the player should still have some sort of say in what happens to the protagonist. Since IF usually does not contain graphics, there is no way for us to deliver the sort of RPG that many people play.
The author does not have to give the player absolute free rein over everything about the protagonist. But the player should still be able to have some choice and some control over the protagonist and the protagonist’s actions/thoughts, since it is interactive fiction.
Excellent IF is subjective, but since the author still writes the consequences of every choice, they still have control over the possible MCs that the players can create. Authors don’t have to forgo anything. The market, however, is another story.
Which definition of artistic are we using? IF is artistic in its own right, I think.