The problem with dark background sites is that almost every content oriented site that's popular use light backgrounds. If you spend most of your time looking

The problem with dark background sites is that almost every content oriented site that's popular use light backgrounds. If you spend most of your time looking at a light background then switching to a dark background takes a little bit to adjust to. It's more of an issue after you read a long article on a dark background, when you switch to a light background then things look weird for a noticeable amount of time.