This isn't all that surprising. Even when you watch some of your favorite television shows and movies, you'll notice that the characters that have the sharpest tongues, violent tendencies, and dark sides are sometimes the most fascinating to watch. There's an appeal, and it's because they have the traits that are considered antisocial and go against the grain, sometimes displaying actions and saying words that we may fantasize about but know we can't carry through on them. If we did, we might destroy many relationships, get fired, and maybe end up in prison!
When I think of Jorge Hernandez, the first word that comes to mind is powerful. The second word is confident. These two traits rarely wane while writing about him. This is what draws other characters to him in the series. This is also what draws readers to this series. In a world where we increasingly feel like it's hard to find our footing on the ground, there's something incredible about reading about or watching a character who is scared of nothing.
Jorge Hernandez is also solid and loyal, often to the degree where he becomes barbaric to protect his family. As much as people may be disturbed by violence, I think most of us appreciate the undying loyalty this character displays this trait, especially in a world where it has become increasingly rare.