I think this is a way where sometimes authors can shoot themselves in the foot. Let me elaborate, this is not aimed at you, but your comment made me realize something that has annoyed me for quite a while (and is relevant to the thread).
Choice. Choices are nice. Choices that allow you to decide how your character feels about things are even better, in fact, one of my favorites. However… it is so VERY easy to add choices never really followed through on. To use the example above, it’s really nothing to to add a choice early in the game that the character in question isn’t really fond of being a spy. It’s good character building, it might allow cool tension, but it becomes a problem when the author doesn’t follow through. Believe me, I know the problems of branching, but it is so VERY easy to unwittingly sabotage some players.
Why? Because at that point in the story, the player has no idea what the story will be about other than in general terms. If given three choices, one that they love spying, one that they like being good at their job, and one being that they just do it for cash and want out, they will assume they are all valid choices that will have consequences. The author might just have seen it as a flavor choice to add choices to a long scene, but for the player that suddenly became a defining trait. And thus, if said defining trait is not brought up in the rest of the story, it is very easy to disconnect players.
So, my advice to all the authors reading this would be to think CAREFULLY about what motivational/skills/goal choices you have early in the story. Let the players build a character within YOUR parameters, and make sure you don’t add choices for flavor without considering the consequences. You can’t do anything for people bringing an existing OC into your game, but you can mitigate the damage.