Don't understand this statement? Been playing the game for many hours a night since the Monday before release. Yes it has some bugs? Is it unplayable? No.
I made an analogy about this very problem. Let's say you are playing a computer chess game. The AI can move it's pieces, turns work, the basic mechanics. But, the AI's tactic is just to move it's pieces to your side of the board. It won't try to take any of your pieces and will randomly pick a piece and move it forward. So, although one could argue "The game is playable", but after you realize the AI is not trying to win the game, how long can you play it?
I mean if you like to take elemental as a citybuilder sandbox game for now, yeah, and it's true that one can experiment and test the tech trees, differences between Kingdowm & Empire. But this is just that, experimentation/exploration.
I personally find it a little disapointing to invest hours in a large map game, to find that the AI horded crazy amounts of towns and armies, declares war on me, and well... just sits there. "waiting". Or worse, you mount a large invasion, take 1 town, 2 towns... and by the gods, the AI might not even "care".
So yeah, let's not be splitting hairs here. The game is "PLAYABLE" but in terms of the AI, there are some major issues at hand which could "arguably" make the game "unplayable" when taking into account certain factors.