“We had made reservations a day before since they don’t accept walk-ins. Upon entering the restaurant, we were surprised at how empty it was. There were only four tables and we were literally the only customers.”
Surprise! He only needs on idiot a day! 
Someone here once said something along the lines of, “If locals can only justify spending money on something once a week, they’ll likely only buy it once a month or two.” This has held pretty true since I’ve looked out for it. My family wanted to visit a nice (costly) restaurant in Tamsui, with a good menu and great staff. Of the dozens of available tables, only about 4 were occupied. Including ours. On the weekend, with perfect weather.
And that was about $200US for 7 people. This doesn’t surprise me at all. I wouldn’t be surprised if you’re right, considering how much smaller their shop is compared to the one I mentioned, this one idiot alone probably covered their experiences for the entire week.
Soups are at its best after 3-6 hours of cooking.
Unless the store sells 20 liters of that soup a day, it can’t be this good.