I agree with the Fyron's argument too...
A challenging AI for a complex game is a lot more complex to create.
A feature that some beta testers (like me), suggested to Aaron, was to include some kind of language that we could use to "programm" the AI ourselves...
Can remember that "Stars! Supernova" was moving in that direction, and also their creators said that the AI had learning capabilities (God, really would liked to see this game in my HD!), and know that an underground game named "Solar Vengance" (
http://www.silicmdr.com./solven.htm) have the feature to program the AI.
Really I would love to have a tool like this... and know that many people would be happy to create a more complex scripts to improve the AIs.