A member of the XDA forums found code on Android 4.4.1 that was written to disable the translucent bars on the Nexus 10. A comment written about the code notes that the feature works poorly on the 10 inch stock Android slab. The XDA member also wonders if the problem is with the GPU or the 2560 X 1600 resolution screen. Another XDA member had a different theory, saying that since the Nexus 10 cannot handle overlaying one object on top of another, this produces the graphical glitches with the translucent bars.
Developers will be able to tweak the code to bring back the translucent bars if so desired, but it will not be the default position for the Nexus 10. It should be pointed out that this is not a problem at all for the just launched Nexus 5 handset and the Nexus 7 (2013) tablet.
Android 4.4.1 brings changes to the Nexus 10
1. Android 4.4 uses translucent bars
2. Code shows that in Android 4.4.1, the translucent bars have been disabled on the Nexus 10
source: XDA via SlashGear