Question???

This is a question for men (white men in general)but anyone can answer it for me. I am just curious about something, we r all on here for a specific reason and that is to find someone true and real to find to be apart of our lives correct? Some of us r on here for just other reasons but the majority r really trying to find someone loving, so how come some of u never list black women under ur choices for race? I look at some men's profiles and I get so hurt and discouraged because race isnt important to me but when i see a white man's profile and he list every race except straight black but he will say mixed race im like confused.Maybe I am taking it wrong but when i read a mans profile and he seems to be all that i am looking for in a man and i see under his ethnic choices for a woman i see everything but black what am I supposed think? Can someone explain it to me, I mean what does it mean by mixed, u r willing to date a mixed race woman that could mean many types of mixed woman but what about just a regular black woman? This is why I am getting so discouraged with the whole dating thing or even trying to find anyone because if u r alone and loney and someone genuine takes an intrest in u but u turn them down because they r missing 1 out of 10 of the characteristics ur looking for and u never give them a chance to get to know them how r u ever gonna know if that person could have been the one for u? Maybe someone can shed some light on this for me or clear it up a lil better for me. Thanks for listening