Wakelock Detector's Facebook page states:
So Finally Google completely restricted access for Battery statistics starting from 4.4 KitKat.
Many battery saving apps are going to suffer from this.
Not only developers, Also users will have No Freedom to use their own way of saving battery.
What kind of sensitive private info could be possibly retrieved from battery stats..
BetterBatteryStats says something similar in their Play Store listing, "* BetterBatteryStats does currently not work with KitKat. Google has made some changes breaking the access to the stats BBS (and other tools) are using. We are working hard on finding a solution but the fix isn't trivial. Please be patient. *"
Frankly, if the only solution is to be rooted, I think I will most likely pass.