Great insights. The gaming experience and pathfinding relationship can also be expanded to game AI in general. I found Lars Liden's slides specifically mentioning "intelligence! = fun". So, for a better gaming experience, it is better to dumb down the AI.
Well, it really depends on the game and user. Personally I'd love smarter AI in some of my games, for some enemies (I realize that I'd probably hate smart AI in other games).
Like, StarCraft skirmish AI is pretty basic, having a smarter opponent to practice against would be nice. As it stands, I can practice a build vs the AI just to get the timings right, but otherwise the AI is mostly useless because it sucks too much compared to a regular player.
https://www.slideshare.net/_Lars_/ai-talk