If you tried to shove tactical battles directly into the game core then yes. It would be possible to create a seperate 'mini battle game' similar to what is used in that old game 'Lords of the realm 2' It is a turn based game but with real time mini battles. You can choose to auto calculate the battle if you don't wan't to take the feild. Not that i am suggesting it is somthing i would want in Galciv, but just to show that it would be possible unlike what you suggest.
The AI would not be able to win the tactical battle against an experienced human player. lets say there are two fleets of 16 ships apiece (16*16) with 4 unique tactics (32*4) with weapons facing and 4 weapons per ship (16*4*4(facing))*16*4*4) on a grid that was 16 by 16 (16*16-32) by 10 turns with each ship having 4 movement points with facing costing nothing to change 16*4*4 per fleet therefore:
16*16 ship interactions
32*4 tactical choice interactions
16*4*4*16*4*4 weapon interactions
2(16*4*4)^10 movement interactions in an 16*16-32 sized field.
Now there are admittedly a huge number of interactions that can be pruned to simplify the problem space but we are pruning the following number just for movement: 2417851639229258349412352
This problem is beyond the realm of a desktop computer to optimize in any amount of reasonable time. Therefore the computer moves will have to be scripted and once scripted the players will figure them out and will win every tactical battle every time so why even bother implementing them in the first place when we can get other features.
Multiplay already works using cheat codes but only on the same machine. Nothing more needs to be said
And the AI breaks down trying to deal with two players. So the players end up competing with one another and either destroying the AI or not playing against it in the first place. Now this may not be a concern for multiplayer fanatics as they all think the AI sucks anyway

, but I paid for a TBS to play by myself with the best AI written for such a game. If I want to play multiplayer and get hacked and cheated on and end up having to quit half way through because my opponent has a real life to live I will play CIV4 modified to be spacey.
Your post is a little narrow minded for somone with your alleged experience.
no more narrow minded than:
Now - where's the multiplayer? This is not 1994 anymore people.
This is 2010. Well, almost. 2007 Quarter three.
Quit making excuses. No one is asking Stardock to host a mp infrastructure - use Gamespy for that. Just add mp into the game.
My experience pays the bills for a family of 4 living in a 5 bedroom house in Virginia on 1 salary. I could go on about this topic forever but I had hoped that:
Before anyone says that the AI SUCKS lets see their high score in the Metaverse playing the Iconians on Suicidal as a Good(ethics) player.
.....Chirp....Chirp....
Would have indicated that the post was to be understood as a combination of sarcasm and bitter experience with companies like Firaxis that had caved to the incessant whining of Multiplayer Bigots who think that human to human competitive interactions are best mediated by computer and not face to face. Oh how fondly I recall my college days drinking beer and playing Advanced Squad Leader with my Comp Sci buddies.