I'm sure for some people, naivety is a 'core trait', but I think for most, it's more of a perspective that's tempered by experience. Lots of people can identify with it, and have learned from it, and it makes for a good character arc.
At risk of sounding self-righteous, I think all of that seems like the player's issue; integrating themselves into the MC too hard to the point where they're sensitive to plot turns or character flaws and what not; and, imo, failing to sympathize with Guy's mistake. Guy clearly isn't dumb, that's proven in later chapters. He just made a mistake. This seems to be a common theme not just here, but in general in internet comments; someone makes a critical mistake, and you have a wall of people calling them stupid. I don't want to assume too much or come off as insulting, but I wonder if sometimes this is a projection of the player's own insecurities, i.e. they've held themselves to such high standards that fucking up like a normal person makes them a moron, and in turn are repugned by a character who isn't some hypercompetent hero genius.
Well, I wouldn't quite say that. Some people get violent with alcohol because they have repressed anger or trauma. They might not be inherently violent, but bottled up emotions always come out violently.
And as for drugs, and wealth, and power, personally, I see most people as very complex and nuanced, and I think those things can tempt you in ways you aren't accustomed to, or drag your mind to darker places that you'd normally resist. The 'real you' is the person you fight to be every day in sobered thought, imo. Drugs and wealth and power can lose that fight for you.
It's like if you're married, and then suddenly a bus full of supermodels want to fuck you... you going to deny them to keep your vows intact? Or are you going to crumble to a fantasy you've had your entire life? Probably the latter. But, maybe the guilt eats you, maybe you lose your cherished marriage, and so on. But the next time you're married and that second bus load of even hotter supermodels stop by, maybe you've grown enough as a person to resist it. I hope I'm making sense.