I'm guessing that you're some combination of "not poor" and "not from the US."

I'm no longer poor, but I do travel through the continental US on a regular basis. Even though my workplace reimburses me for food when I travel and budget doesn't enter into the equation, I eat fast food fairly frequently.

Scenario A) I've been though a series of planes, airports, and rental cars for the last eight hours. I'm in central Iowa, I've just checked into my hotel, and there's a major winter storm 30 minutes away. Non-fast food takeout isn't an option because this town has 20,000 people in it and I would need to travel for an hour to find a larger town. I could find a nice local restaurant, but there's an Arby's that's a block away from my hotel. Since my priorities are 1) putting some warm food into my face, 2) not driving through snow, and 3) going to sleep, it's Arby's.

Scenario B) I'm driving back home from Chicago, which is about a 7-hour trip by interstate highway. I'm in the scary part of Indiana when I realize that I'm hungry and still hours away from civilization. Food options are a) fast food and b) truck stop food. That last option is basically "unknown fast food with an unreadable label that's been sitting in a heated tray for 4 hours."

Scenario C) I'm in a small southern city that I've never visited. My plane was delayed and my luggage is lost. The rental agency couldn't find the car that I had reserved, so I'm driving a lifted pickup through dark and unfamiliar streets. By the time I finish shopping for some basic overnight things (deodorant, hairbrush, underclothing for the next day), it's 9:45 and most nearby restaurants are closing. Five Guys is a block from the hotel and because they close at 10, I can either choose that or try finding and walking to a restaurant that's open later.

Those are all examples from this year. Basically, takeout options outside of major cities are horrible. In small cities, most places - if they even exist - close earlier than fast food chains. If I have the time and energy I'll absolutely find the nicest local restaurant and enjoy some regional cuisine. And under normal travel circumstances, that's exactly what I do. But sometimes you just need to put warm food into your mouth and get to sleep.