The only place its an issue for me is within the photos app, if you take landscape photos you end up with white borders either side of the photo which is quite distracting
It´s certainly an issue for me. I just feel that readability is diminished in the white background with black fonts. It´s easier for heavy usage to have a black background with white or gray fonts. It´s also a simple diferentiation between paper and digital. I love my phone but I do envy seeing the all dark interface of some android devices.