I'm a well read grad student who's bluntly honest about all things, although I try to be most honest about myself.
Spider-Gwen is never afraid of shying away from darkness, from the creepy versions of Matt Murdock, Wolverine, and Kitty Pryde, to how S.H.I.E.L.D is run, to the situations it puts Gwen in: she has to compromise herself for the safety of others often enough that I wonder how she keeps it together, sometimes. She makes deals with Murdock, who is the de-facto Kingpin for now, to save her father. She almost sells her soul again for Harry Osborne, but instead runs away with him, only to be cornered by Logan and Kitty once again. (And I thought Murdock was the creepiest, but nope, these two have him beat.)
Maybe it's just fun because I know there are alternate versions of them running around, versions that I like, who would be appalled by this. And while it's never fully divulged how these characters became this way - the focus is Gwen after all - it's easy to piece together some of it from the universe they live in. Without Xavier, under the not-so-gentle hand of this S.H.I.E.L.D, yeah, Logan could become totally soulless. Even just without Xavier, he could be trained to be the monster he's become here.
Murdock could have been persuaded by Fisk that this was best for him without any other guidance. Lack of support, lack of role models after his father's death, could have twisted him around, too. And even in 616, it's made clear that he idolized his father, who used his fists to make a living as a boxer, and would resort to fighting at school when he'd hit his limit. (His father told him not to, and Matt got punished for it, but had the tendency, possibly just through watching his father in the ring.) If someone decided to tease that into a purely sadistic tendency...
Frank Castle is dark even with his family alive, and to be honest, he's the one who I'd most like to see again, just to see why he still turned out to be a psychopathic vigilante. But he's not in this.
Regardless, that's part of the charm for this series for me, and it's used to full advantage with Murdock, Wolvie, and Kitty, and even with Harry who's becoming The Lizard once again. Perhaps Gwen's guidance - telling him he can't steal when his literal reptilian is only focused on survival. It's wrong, and more than that, it could show their hand to those tracking them, she points out. His answer? More for me.
Still, it would be fascinating if I was proven right: if Gwen can reform someone with such a guiding hand, it might mean that all the people who are broken and creepy and dark are so because they didn't have that in this universe. (Or maybe they're just utter bastards here. Who knows at this point? Either way, it's fun speculating and I'm enjoying reading this series.)