Great god, about time someone reported this.
I forgot to do this myself, too busy playing the game(cough)... then I suddenly remembered and came here to see if anybody reported this already.
I don't have a savefile, but I can confirm this happened in every single bloomin' game I've played thus far.
The AI typically does: worker, worker or settler, run to the nearest spot, found a city.
Oh, and I have raging barbs on, and there are at least five barb units running around anybody's city at any time while that's happening.