Hmmm...I think I may have misinterpretted your original post. I thought you were actually talking about "speed of game" (ie it runs at 2X, 4X..etc by hitting "+" and "-" buttons) not "Speed of research/economy/metal/crystal" (settings of slow, normal, fast).
The option you are asking for is for faster economy based items. To me that is just seems like it is turning into a frantic continuous building cycle. If you have nearly unlimited funds that you don't have to "work" for it eliminates 2 of the 4X (eXpand and eXploit) turning into (eXplore and eXterminate).
The fact that games can be won, empires can fall, fleets be destroyed, speaks toward the present balance established by the devs between construction and destruction. Otherwise games might fall into a perpetual cycle of cat-and-mouse (get destroyed, build anew, get destroyed, build anew...).
Ironic you should say that...because I was trying to say that the current mechanics ARE a cat-and-mouse cycle on the small scale. Of course if you have overwhelming numbers the mouse is dead instantly.
If the production time takes only a fraction the battle time (very unrealistic, as previously stated) the "balance" is severely disrupted. I can "suspend my belief" on many things...especially if it makes the game more balanced...but in this case you are asking me to "suspend my disbelief" so that the game can remain unbalanced. This negates the ability of running sabatoge missions...a key element of any good strategy game.
To me the game has just seemed like "build big army...go destroy everyone". Much less "strategy" than typical turned based 4X games. Perhaps that is just a trade off one has to live with when trying to go to RTS from turn-based.