That is the whole point...... preference is a greater liking for one alternative over another or others. Preference is NOT exclusionary or inclusionary.
The most troublesome aspect of racial "preferences" lies in their inclusionary or exclusionary nature and heavy generalizations. It’s totally OK to acknowledge that you’re more attracted to certain traits, but it’s a totally different matter, altogether, to use "preferences" in absolute terms. Checking the dictionary, again, that isn't what preference means. Period.
What troubles me most is, having lived through the "civil rights movement" period of American history, I hear people continuing to use the term "preference" instead of the term "prejudice"....
As in 1964 (And usually prefixed with the words, "I'm not racist, but...."):
It is my preference to use the [insert color] only water fountain....
It is my preference to serve or eat with only [insert color] people in the restaurant....
It is my preference not to send my children to school with those [insert color] people....