…While it's true that your options aren't going to show up in a convenient manner and not a finite amount, I think that saying it's "a good grade" is a bit insulting to the writers who made those characters. The ones without any love put into them are definitely one-dimensional, but there's so many that hold complex characters, and learning how your own actions affect them all differently helps you in real social interactions.

For example, Haruka and Kanade from silentXnightmare both have mirroring options, but their characters are so different from one another that the "correct" options are never the same. Like the one scene where they leave the room and Player Character has a chance to snoop after they're told not to. Haruka values loyalty and will get mad if you do, but Kanade values free will and finds it charming. And this is just a very mild example, considering the routes get way more complex as you go. Like how free will has the price of Kanade's route having waaay more chances to get bad endings, and Haruka's loyalty quests being absolutely heart wrenching if you get the bad endings, and…

…Ehem, anyway, I'm not saying treat him totally like someone that has options occasionally, but Passenger is complex, but he'll also have things he values and differing ways of how he reacts to things. There's not really ever going to be a single "right" way to handle it. To handle people. So it's important to do the things that are important to you, and if things don't go right, maybe the match just isn't right.