Why are we still talking about PASSING?

For some reason, this essay fills me with major frustration and nastiness. I won't go into that for the moment, but suffice it to say that the NYTimes Book Review has published a nice little literary essay on racial passing. Perhaps for NYTimes readers this is a new topic, but it is old old old and slightly tired within intellectual/academic/literary circles. Not that there is any problem with old old old... In any case, the essay concludes with the following paragraph:

I don’t hate the real or fictional racial refugees who abandoned the tribe. I can understand the desire not to have your life conscripted by race. What I can’t understand is the other side of passing, the road more rarely traveled. From my perspective, it seems many white Americans are entranced by blackness and drool over how exciting and dangerous and sexy blacks seem. So my question is: Why aren’t more white people trying to pass as black?

The problem with this paragraph is an assumption that we know who's "really" white and who's "really" black. This was the assumption of the last century. But come on, if people have one (visibly) black and one (visibly) white parent, why do we continue to speak about "passing" as white OR black? Shouldn't we be talking about... oh I don't know... something else... Inhabiting black or white roles? Stereotypes and categories? Embracing tics or fashions or lingo or pretensions? Or rejecting parts of one's family? While embracing others...