Twinwillow got the issue exactly right. The owner clears < 50 cents per $8-10 buffet plate after taxes, health insurance, Social Security, laundry, cleaning costs, labor, etc. are met.
In every big city there is the inescapable organized crime "rent" to be paid, too. In the US, it is all very civilized & institutionalized, i.e. you hire XYZ garbage company, PQR produce supplier & so on.
Therefore, unless there is a good night time crowd who spend on higher price items & drinks, the restaurant cannot function. Americans are conditioned to associate "Indian" with "cheap food", so in the smaller cities, unless there are Indians or subcontinentals ordering their favorites, there will be no call for the high-ticket menu items.
Additionally, it is very difficult to get a truly good chef from India to come here owing to visa & wage issues. Most smaller restaurants run with amateur staff or Hispanics hurriedly trained to be cooks. I know this because I was an Indian knowing scarcely anything about Thai food promoted within 2 days of joining to sous chef in a Lao-Thai restaurant!!!!! No one could tell the difference, and I wondered, WT......!!
So now you can appreciate that the buffet table is just one aspect of a complex operation. In fact, not having one would give the staff that much more rest and prep time from 2 p.m. onward, and a more relaxed atmosphere to clean the premises & get ready for the 5 p.m. opening. Remember that staff do not get to go home until at least 2 a.m. IF they are lucky!