Well if you install that you can see the same things that are impossible to get over:
- calendar event view has white text that cannot be changed into a different color => white background won't work since you cannot read the dates and times (white on white)
- top bar has white icons (wlan, battery, network indicator) that are hardly readable on white background

So what if we change just the background to dark? Let's do that, then we need to have the basic font being white so that you can read stuff from all other programs. Cool, let's do that and keep white top bar and white buttons.
But wait a minute, we need to have a dark top bar because it's good to be able to see the network strenght etc. So let's make the top bar also dark and change the font over there to white but let's keep the buttons still white. Wrong! Some button texts uses the same color that top bar font has so we cannot have even the buttons being white since the top bar has white font :-D

Case closed :-P