Alright just for kicks, and given the infinitesimal chance that you are truly curious and not a troll I will give you an answer. First, the vast majority of men here in my experience with the site are looking for certain qualities, attributes and characteristics in a woman. These qualities, attributes and characteristics know no color, and the majority of men here would happily date a woman who meet these criterion regardless of how much melanin she has in the epidermal layer of her skin. The life experience and sometimes just plain geography (as well as a thousand other reasons) of the men here have led them to be interested in the kind of women found here on this site. In other words they date them for the same reason anybody dates anyone, love and having a lot in common.
The reason you got the initial negative push back to your original post was that you made an insulting ASSUMPTION that the men and women here were not getting something from a certain group women/men and ran to another group of women/men. There was also a subtle attempted shaming tactic behind your words imho as well, not a nice way to introduce yourself, and not original at all, countless trolls have done drive-bys here asking similar if not the same question, all with twisted, sick, bigoted agendas to push.
The bottom line is this, there is only one race, human, the dividing, stereotyping, ect., of human beings into "racial" categories based on appearance that we still see so often across the globe, is a social, not scientific construct that has always been used by those with power (political and wealth) to control the hearts and minds of those two are too stupid or scared to think for themselves.
http://www.pbs.org/race/000_General/000_00-Home.htm