I have suspicions.
I suspect that the AI's development has been hampered by the tools it has been given to appraise the strategic situation and that it will continue to be hampered in the future unless those tools are improved.
Good decisions require good information.
If I'm not mistaken, the AI's decisions are greatly influenced by power rankings.
I suspect that the equations for determining player's power rankings were thrown together in Alpha and never revisited.
As you can tell, I'm a very suspicious person.
Given the gripes I often hear on the forums about the AI, and my own experience playing the game, I think it could use some work.
Just throwing it out there that work on the AI might best be begun by giving it better tools for its decisions BEFORE working on it's decision making skills.