Because it’s based on understanding. It’s not brainless cuck-morality that asks only that you be a pacifist.
Compare it to say, Bioshock.
“Hey kid, you wanna murder this little girl to earn a little extra? Oh, by the way, if you don’t murder a bunch of little girls, you get rewarded. So basically the question is just ‘Do you want to murder little girls?‘”
Fallout’s even more comical. “Nuke a city or don’t.” There’s nothing wrong with separating morality into “Obvious good, obvious bad.” But it’s just not as interesting.
Metro 2033 asks that you listen to conversations and explore. And it actually doesn’t ask, which makes it better. The wiki explains it better than me;
“Moral Points form a hidden system in the Metro Video Game Series that follows Artyom’s progress and affects the ending of each game. This system is never explained to the player and its mechanics can only be speculated about. As Metro is about Artyom’s journey and him seeking to understand the world around him, the game rewards the player for guiding Artyom through experiences that help him better understand the metro and its strange phenomena.”
Yes, some of it’s basic good deeds “Help out this little kid because it’s good. Give this beggar a cartridge because it’s good. Don’t kill everyone.” A lot of people insist that it rewards pacifism. And even though I believe that, I’ve also killed literally everyone in playthroughs and still gotten the “Enlightened” ending, while I’ve seen people complain they haven’t gotten it despite not killing anyone. That’s why it’s not called “The Good Boy” ending. The system is more about exploration and understanding than “killing bad, pacifism good”. There’s not a lot of opportunities for you to lose moral points. But on the other hand, there’s a huge amount of opportunities for you to miss out on getting them in the first place by being an impatient brainlet- not listening to the voices of the dead in the pipes, not asking whether something strange is hostile or not before you shoot at it. And it’s even nuanced, so just being an autistic completionist exhausting dialogue options isn’t necessarily rewarding (even though it often is)– bothering someone when you’ve already been asked to go away will lose you a point.
It’s not always perfect, because it rewards you for rescuing Communists and punishes you for getting a lap dance. Fine, it’s not right to just sit back and let people be executed because they’re idealists. But it was just a lap dance. Still, it’s a great system and I love it because it ingeniously encourages you to explore, and not just explore but to do so thoughtfully. Except when it comes to lap dances.