My impression is that game AI (and I mean in FPS, not board games) were not considered as serious AI in the computer science sense. Most game AI even till this day are “cheating” in the sense that they are not end-to-end (i.e. cannot operate using screen capture, vs. engine information), and often also need additional advantages to hold ground. For example, virtually all these FPS game AI are quite useless once you actually want to interface it with some form of robotics and do open world exploration. So game AI is somewhat separate from the public’s obsession with the term AI, that suddenly turn nit-picky/moving-the-goalposty once AI became performant on end-to-end tasks.

The Wikipedia article AI effect (not super-polished) has many good references where people discussed how this is related to anthropocentrism, and people can also be very pushy with that view in the context of animal cognition:

Michael Kearns suggests that "people subconsciously are trying to preserve for themselves some special role in the universe".[20] By discounting artificial intelligence people can continue to feel unique and special. Kearns argues that the change in perception known as the AI effect can be traced to the mystery being removed from the system. In being able to trace the cause of events implies that it's a form of automation rather than intelligence.

A related effect has been noted in the history of animal cognition and in consciousness studies, where every time a capacity formerly thought as uniquely human is discovered in animals, (e.g. the ability to make tools, or passing the mirror test), the overall importance of that capacity is deprecated.[citation needed]

Note that there is also a similar effect, not explicitly discussed by that article, where people like to depict ancient societies dumber than they actually are (e.g. the today discounted notion of “Dark Ages”).