Yeah, sometimes it gets crowded that you have to be a tough and quick to catch a turn in the line I personally don't do that and come in the middle of the service time between prayers (store here close at prayer times. But it's not a big deal really).
The price is a huge factor indeed. But when that's combined with quality product and quality service, it is even better and more worth it. Dining-in halls are typically huge in their branches, and their big branches have dining halls easily bigger than 15m x 15m. Mineral drinking water in coolers is free and cold, you can ask for more bread and garlic sauce as needed and their halls are so clean and pleasant in the infernal weather we typically have here.
Grilled and roast chicken (Al Baik has only fried) around the country is even cheaper. Whole 900-1,000G grilled chicken is typically $5.4 USD and whole roast chicken is typically $4.8 USD. Chicken in general here is cheap. Poultry (fish and shrimp in the fish market is kinda cheap too) is a popular local business here. They should consider turkey too
However, one could easily make similar assertions about our black Friday mob crap that goes in at many major retailers. Perhaps we see this as so ridiculous because of the wide spread availability of many fast food chains? To the comment above about waiting more than 5 minutes and going somewhere else... same here. Because there's somewhere else that's same or better within (not literally) a stone's throw in any direction. So perhaps seeing something like what we take as common place being introduced ... we find it to be a wild sight.