Clearly this is an older post, but I'd like to voice my opinion as well. Multiplayer is something that I would absolutely love to have in this game. I have doubts about the method used to collect people's opinion concerning multiplayer as well, as there are some out there who refused to buy the game due to a lack of multiplayer, and thus most wouldn't be involved in the poll concerning whether people want it or not. I have at least two friends (subjective, I know) who don't have the game for the very reason that it doesn't contain multiplayer. I myself held off for years for that very reason, and I'm almost certain that we can't be alone in this.
As for the argument that the game would be limited in same way due to multiplayer, I have my doubts. There have been statements made that the AIs treat the player like it treats one another, so that shouldn't be an issue. As well, the random events can be disabled already via the UI, and if they occurred I imagine that players would have a similar reaction as the AI would (going to war to stop someone from developing some super tech, so on). Basically, the arguments presented were compelling only so far as the base game went, but far from it for an expansion. All of the features are in the game already that were listed as reasons against multiplayer, and now that they're there they would no longer detract from the development of a multiplayer experience.
Just wanted to toss my voice in there, and maybe see this thread get some more traction again. I doubt that we'll see multiplayer, but I don't doubt that it would mean fun for many and money for the devs if we did.