There are many kinds of evil, and also the morally gray. Evil doesn’t have to be evil just for the sake of it.
At the end of the day, these kinds of videogames tell stories, and a story full with nonsensical evil will only appeal to those freaks you talked about. In the other hand, if it is handled correctly, the story will appeal to a much broader audience. As an example, at the end of The Last Of Us (the show, idk about the game), the main character refuses to save the world because it would mean the death of the only family he had left, and massacres a lot of people in a mix of survival instinct and paternalistic rage. It is horrible from a moral perspective yet it is a good, engaging story.
I feel like, in the same sense, a character with impenetrable morality and no conflict would not be very entertaining to read/watch/play.
As for the workload, I’d rather they didn’t give me the option to be evil if the story is going to be bad. The devs themselves choose to make different paths, so at least have them be equally fun. (I’m not getting into pressures from above for “branching narratives” or any other marketable terms. Replace devs with “studios” if you wish.)
Adding to the other comment, I feel like you can get a taste for all that by visiting the game’s subreddit. Seeing all the cool things people do and how the community moves the story forward really motivates me to play the game. I guess you could also watch a youtube video to get up to date on the story and different ways to play the game.
It is a great game but you really do need to look stuff up to fully enjoy it, unfortunately. Also, space trucking is only one way to play it.