I only know my particular feeling about this. I have the sense that most mentions are of black and white images, either film-based or looking like it and maybe a wee bit of the same people being mentioned every week as in a mutual admiration society. Looking at the pictures above this post, I see that the ratio of B+W to color is 12:1.
But, I have jumped in at times and named my favorites (once I figured out how to do it) and have been fortunate to be mentioned often enough so I will continue to do so. This is still a good site for seeing some outstanding images. It just seems to me that it could be opened up a little to be more inclusive.