The reason why I say that making "biracial" a separate racial category is because it has increased racial categories at a time that we should be reducing racial categories. Creating a whole new identity group does not mitigate the problem of identity politics.
If I were to suggest we stop racial categorization altogether....I think a lot of people would resist the idea.
I would suspect that we would probably find a group of people of any color who would immediately be suspicious of the motive behind the suggestion.
Is it to hide racial oppression? To disguise racial subversion?
I could rationally explain why constantly referring to racial categories reinforces them as significant social differences far past the point where they are accurate or meaningful.
That won't change how people feel about it though.
And black people did not do this. White people--specifically white mothers of biracial children--did this. "Biracial" wasn't even a social concept prior to the 90s. It wasn't until the 90s that the US did what South Africa had done: Create a whole additional racial identity group.
Words referring to bi and multiracial categories are far older than the 90s RD.
Mulatto is a word hundreds of years old that attempts to categorize the same phenomenon you seem to think began in the 90s.
The problem is not the phenomenon it's the attempt to create a distinct categorization of it. People can be distinct at the ethnic-socio-cultural level for a lot of reasons. At the genetic level, we are simply too similar to easily or meaningfully tell apart. The idea of race as a meaningful biological foundation between ethnic, social, or cultural groups is the result of a group of people who increasingly tried to find rational explanations for what these socio-cultural-ethnic were. A lot of racial categorizations were proposed including the "main 3" type that you referred to briefly. The Negroid-Caucazoid-Mongoliod distinction between cranial shapes, hip width, and height (I think, it's been awhile since I read about it) is a result created by geography and as far as I know, not a meaningful distinction.
There is only a few tiny measurable averages that science has been able to find and they don't seem to be based in biology...or at least no one wants to claim they are. Science seems pretty confident they aren't. They typically aren't talked about, because of the stigma that results.
It wasn't an issue for black people until white people started recognizing biracial children as a separate--and preferred--racial identity group. Until the 90s, these were black people, and they identified as black people (which is why there tends to be a cutoff of self-identification for those who are currently 45 or older).
Again, I'm not blaming you for your views here RD.
You don't have to try to justify them.
And it's a mistake to think that it doesn't matter. We have seen a whole new facet of racism appear as "biracial" is accepted as filling the "racial diversity" square, particularly in the media...but it also happens in business.
How does it matter?
Now, to some extent, it can be a cultural issue, or at least a "cultural comfort" issue. A biracial person is more likely to have more fully adopted Anglo-American culture and will be more comfortable to white people (sometimes too comfortable when they forget he's there, as Jesse Williams reports).
....
At this point in America, biracial categorization has merely put a "no-man's land" between blacks and whites.
I don't think it does. I don't know what a biracial or multiracial person thinks nor would I bother trying to assume such things. I tried not to assume such things about you when I learned that you are black.
Any such assumptions may feel tempting because they create any easy framework and pattern of categories that we believe is more reliable than it actually is. I think I can safely say that you have an idea of blackness....and while you certainly include people who you might describe as "the exception" you also imagine a large amount of similarity in "the norm".
It's not your fault you see things this way. Almost everyone sees things this way. It's a result of a biology that has used pattern seeking as a defense against a hostile world. The people who came up with race weren't even aware of the basic level of pattern seeking that was directing their observations and attempts at categorizing. It's not really anyone's fault.
We can imagine individual tribes of early humans with primitive languages separating when they grow too large, traveling to avoid conflict and growing into unique yet similar traditions and eventually cultures. When they once again, bump into another tribe at that point they have a need to use a word to describe themselves and the other tribe. The category is created by necessity. The distinction between self and other is real. The meaning of the culture and traditions are created. The differences beyond that are imaginary.
Does that make sense?
If you understand that is how it went, and we have plenty of evidence for it...then you can understand that the only thing different about the category of race is the degree of rationality behind it. It's not a spiritual distinction, nor is it a philosophical one. It was thought to reside in factual reality.
That's why it was so easily propagated...but it's also why it's falsified. We can just let it go.