The syrup, for example, is basically high-fructose corn syrup with added flavouring. So is the ketchup. I didn't sample the entire menu but the overwhelming impression was of it being composed of the cheapest edible food-like substances known to science. It didn't feel to me like a time machine back to an era of cheap-and-cheerful diners that served real honest food, but rather depressingly contemporary.
And yet there must be something there. Something that prompts folks like you to genuinely see it as not just a chemical amalgamation, even though by any objective standard it really is. Something that I missed. (The place was deserted at the time when I went, so maybe that was it.) Something that makes me still wonder if I should go back and search for it, even though I don't know what I'm looking for.