Hello orangecrush. I too grew up in a small town in NW PA (perhaps not very small, since we had a college and were the county seat, but about 6-10K population), but I also had a lot of friends who were outside of the "librul" influence of the college, including some who have made national news. I've also seen this sort of behavior with churches in Western Michigan, and Montgomery County MD. I don't think it is exclusive to this part of PA, it is a pattern of certain types of people preying on and taking advantage of a part of the vulnerable population for their own goals.
I've seen firsthand how church building occurs. It's not easy, especially if you want to abide by traditional church doctrine. The church I joined after moving to my first job seemed like a decent and reasonable place. And then they got kinda weird. It wasn't just the talking in tongues, or the personal demands. That wasn't enough, so some members decided to form one of these store front churches, which they did. I have no idea if they are still around, but I doubt they are.
In any case, my sister was taken in by one of these groups, which is when I found out I was going to hell for reading Harry Potter. She has come to her senses, and regrets her involvement.
But in general, they are organizations that helps the people that society and the government don't. They are the only organization that will help them out, so their message is truth. I think this is the most important point: If you are separated from society, society has failed you, the government has failed you, you are looked down on by friends and family, and the storefront "church" helps you out and tells you why your problems aren't your fault, you listen.
tl;dr: Poverty breeds desperation. With desperation comes people to prey on that vulnerable population. What you see is the end result.