Maybe they added this feature because when you dim your dash lights with the dimmer switch, the radio does not dim at all. So if you dim your dash lights all the way down, and then pull out the Balance control to turn off the illumination on the radio, then everything around your dash will be dark. Maybe some people like to drive with their interior lighting in "stealth" mode at night.
I noticed the procedure for dimming the radio is in the owner's manual.
I noticed the procedure for dimming the radio is in the owner's manual.
