Is there any reason a Black woman and Mexican guy cannot date??

So I am a light skin Black woman (I am often mistaken for Latina). My fiance is Mexican (he is a white mexican, he is more Spanish than he is Aztec or Mayan). I was wondering if anyone can explain to me why some people view this relationship as wrong (my main concern is within my family). Is there any logical reason why to people can't date because something as minor as skin color.