One of the new “features” of iOS 6 is that you can now tint the status bar. Instead of Default (Grey), Black Transparent, or Black Opaque it can now be anything.
The way iOS decides what color the status bar should be is based on the color of the lowest pixel of a UINavigationBar component. Source
In a Cordova application, or any fullscreen UIWebView app, there’s no UINavigationBar by default, thus no way to tint the status bar.
There is a simple “hack” though that you can employ to get your status bar tinted, you only have to sacrifice one row of pixels.