If he joined that gang, he probably would actually found his relatively safe place where he could stay, too bad he'd hate committing evil acts on the regular, so he's gotta get out of it. Like, even now, in XXI century, there are plenty of places in Latin America that function just like that town when you get to the poorer parts of the city.
This is true about Latin America. I use to live near the southern border to the US. Sometimes I would walk to Mexico*, do shopping or visit a park or museum, and come back. People from the US side thought I was insane for going into cartel territory and told me it hadn't been safe to do so for decades. People from the Mexican side were more realistic about commercial areas being safe, but tried to convince me not to go alone as a foreigner. I didn't follow their advice, but always carefully planned my routes and was back before sundown.
People were friendly but would stick to themselves unless they had a reason to interact with you, like selling something. You never know who you are talking with. If you were in trouble, someone with good intentions would likely help you (especially if you're an old lady, even criminals may help an old lady in Mexico), but you have to hope that they're the first to find you. If you look as intimidating as Yajin then I imagine fewer people will be taking that risk to help if they don't know you.
I never had any bad experiences, but I was very aware that being seen as disrespecting the cartels or encroaching on their business (eg selling drugs, not that I would) could be the end of my life. The border region is important for smuggling, but in other places, they control tourist industry, farming, things like logging, etc. They can be more influential than the local government and people in the local government may work for them. Many people in depressed areas associate criminal organizations with economic and social success and in some cases see them as more trustworthy and effective than the government.
Naturally I'm fairly sheltered as these things go and can't claim to understand it like someone from Mexico, but it was my first exposure to that kind of environment. I can imagine what it would be like to buying fruit from a stall, eating in restaurant, etc and one of these guys shows up.
* Yes, there are official border crossings for pedestrians. Sometimes you pay a small fee depending on where you cross, they may search suitcases/bags, and there may be Mexican army or National Guard with big rifles. One time, when my backpack got searched, they looked at my prescription nasal spray like it was the weirdest thing they had ever seen before silently putting it back in my backpack. It's not US Customs level of security, but there's a procedure. More scrutiny than if you were in a car, I would say.