Just some of the reasons I think this AI tech victory is a bad idea:
1. Any level above intelligent the AI gets bonuses, the human player is always coming from behind, and since noone will want the game to end early, and noone will want their score reduced after playing for hours, people will just disable tech victory, thus making it a change that required effort just to give people a game that is -less- than before the effort.
2. Currently AIs go for military and expansion, that is why they are so competitive. Any AI that is implemented that goes for a tech win is going to be weak compared to the other AIs and thus will be conquered by them. This results in military-oriented AIs gaining momentum faster than before.
3. AIs trade tech that humans wouldn't, what's to stop the Altarians from going tech, the Torians from going military, and then both trading in full? Even on the lower difficulty levels this would be hard to deal with.
4. AI's extort: one AI goes tech, the rest go military, the tech AI is weak so gets extorted for all their final frontier tech, results similar to #3 above except even more civs have the tech.
5. Lack of flexibility when playing. Right now I can start up a game and have no idea which way I'm going to go victory-wise. But if AI tech victory is put in then I know the clock is ticking, I have to choose a -fast- way to victory, or turn off the tech victory condition, either of which leaves me with less of a game then I started with. I don't want to play 'beat the clock' when I start up GalCiv, nor do I want to turn off a victory condition that I might need under certain game conditions.
6. Considering the 3000 things that currently need doing in GalCiv, I consider it a huge waste of the Stardock team's time to implement a 'feature' that gives absolutely nothing and in fact leaves the game less than it was before. A feature that I can damn near guarantee that if it gets implemented will result in the vast majority of players turning off the tech victory condition, because who wants to play for hours only to have the score reduced, or just plain lose, because of the implementation of this 'feature'?
7. Keep in mind, you -have- to militarily defeat a civ to stop it from achieving a tech victory, which is a whole different story from stopping a civ from conquering you (which is the only way they can beat you currently). If all 5 AI civs are going for a tech victory then you have to beat all 5 before any one of them makes it, good luck doing that in a gigantic galaxy unless you play a purely military game from start to finish.