One of the restaurant's employees was able to explain the situation after I raised my question. It turns out that I find myself ordering at the counter rather than being seated because I like to pay at the register when I order, rather than after being served and eating. After being a customer for years, I essentially did not know this was the reason. My preference to pay in advance and hence order at the register makes it more difficult to be sure if I am dining in on a particular visit. When a party wants to eat there, they can always simply ask to be seated to make it clear to cafe personnel. In my case, that would lead to a situation in which it would be more difficult to pay when ordering. A recent visit with relatives in which we were bafflingly seated by wait staff brought the question to mind and led to this helpful answer from the restaurant.