Sabin_Stargem: The calls for complication mystify me. I have played MOO2, and that game had simple rules and procedures for how things were done. It was one of the reasons why I liked the game in the first place.
Options and efficiency. Complexity done right can give you many more viable options to play the game and making your empire more efficient, thus squeezing out more "production" than your opponents is a whole game in itself.
Oh and the call for complexity shouldn't be confused with making games unnecessarily more play unfriendly. It's a bit hard to explain better.
Edit: For example look at Space Empires IV here on GOG. That's more complex than MOO so it gives you many more options on how to be successful. You should try it if you're used to playing MOO. Going from MOO to SE IV is like going from Normal to Advanced. :)