take the fun where you can get it.

Valid objection - as it pertains to "enhancing" the gameplay range (or quality by design, in fact) for x number of users; but sadly, some gamers DO have a knack for concepts that pits them against one another. It doesn't negate the situation of excellent AIs nor does it validate peoples' performance in MP... single player is a contest of personal skills instead of demonstrating HOW it improved or can be matched.

If SD wants any GC3 to be market(s) inclusive, they need to address more than just the SP crowds. The MV was simply a tracking device of activities (best or less) by individuals while result of duel games in tournament matchups is similar to principles delivered through some of the usual scenarios whereas the DreadLords (etc, btw) is controlled by unknown but not algorithmic JoeSchmos from anywhere on Earth.

Now, you'd certainly get some weird Colony Rush stuff and much more than you can imagine. I can only phatom on the incredibly strange Diplomatic & Trading dealings in such a context. Thus, the only competitive AI worth fighting against is a true human being (hot seat or not) wired to an SP1 mindset or reacting as SP2.

SEIV may be instructive.  That 4X game has a multiplayer feature.  MOO2 does, also, sorta'.

On the SEIV Boards, even after I had learned to beat the AIs on the highest levels, I found that my race choices and strategies would not have been competitive against humans honed in human-v-human play.  The same was true for MOO2.

For example, in SEIV, IIRC, if one did not maximize attack bonuses at the cost of almost everything else, one got blitzed early.  Many of the game's neat traits and chrome bits had to be ruthlessly ignored just to be competitive. 

In MOO2, another example, the winning strategy was generally to take the mind control trait, sacrifice everything to build one cruiser-sized warship with a certain missile design, and lunge out in an attempt to find a production-based race homeworld to mind control.  Every other strategy crumbled in the face of it.   You could not choose to be a production race, because it simply made you choice fodder for the mind control "tank rush".  No diplo trait helped.  No choice of stmosphere, or gravity, or anything.

The closest thing to it currently in GalCiv2 is trying to win at Suicidal, and there are more ways than one to win at Suicidal.

If, say, Dark Avatar, gained a retrofitted multi-player capability, we would soon learn just what those same things are that showed up in SEIV and MOO2.  Humans don't care about SCC math artifacts, for example, or Diplomacy bonuses.  So, in a human-only game, no one would bother with Diplo techs or improvements other than to gain the Eco capital improvement.

There would be new aspects, though.  For example, in SEIV, if one empire was revealed to have a certain trait, all others would gang up on it quickly, because if left alone that trait was recognized as producing an unstoppable empire.  In DA, the announcement of a near Influence or Research victory by one race would set off instant wars, essentially preventing Influence wins, and making Research wins tougher, as well.  There might be a need for a new class of Victory, where an Alliance wins if any one member achieves a Research win.

Seconded. Multiplayer is the bane of all single player games. The two are pretty much mutually exclusive, and far more people play single player than multi.