It is immensely popular, especially with bus trips. Has been since the 1960’s. I think it was in the 90’s when they expanded to a 500 person seating area.
Nothing against them, I just dislike small talk and trying to “get through” a meal with someone I don’t know. Same with Hibachi and even parties where I don’t know everyone. Its torture.
Between COVID and the younger generations not really into “family style dining” (honestly, a bulk of their crowd is families with youngish children and senior citizen tour groups), I don’t know what their future will hold. As you said, the concept is a cultural experience. The point of their existence, bringing strangers together for a meal, etc.
