(disclaimer: I am an American whiteboi.)
Because white nationalists are cringe and don't see the big picture.
The problem isn't niggers, or even Jews. Both can be a problem, they are groups of people who disproportionately cause problems, sure. But having loyalty to "white", Western Civilization is cucked as hell. What the fuck has the "white" West ever done for me? Other than give birth to me in this high-tech shithole where I am predestined to be lonely and at the very best wageslave for a 3/10 obese hog and more likely be lonely slaving or NEETing for life.
"Muh people", bitch, white people hate you. The vast, vast majority of "muh white" people would be more likely to laugh, nodding along and agreeing with r/IncelTear posts if shown them than posts from this majority-nonwhite forum, which they would report to the FBI and call the cops on.
Like, sure, there are probably biological differences between races that, on average, make blacks more violent and dumber. They sure as hell make black women uglier

not to mention Indians in general.
But who cares? At the end of the day, we are all people unjustly maligned by a system that holds us all down. Not all of us should even breed, but breeding and having love/relationships are different.
While the left denies reality to maintain female privilege and advocate for a dysgenic order pushed by a combination of Jews and different "interest groups" trying to justify getting more shit than a rational system can empirically handle with a system "built-up" over generations to get those interest groups more unsustainable shit that, while it would be nice if they could freely receive without consequence, the reality is that giving them that shit will destroy every life, including their own, in the long term as the left erodes all of the traditional barriers to social collapse in its effort (in many cases, genuine deluded belief on the part of genuine activists, sometimes it's pure greed of people who know better but don't care, and sometimes it's Jews, who don't have COMPLETE control unlike what stormcels will tell you, but have a disproportionate amount, greater than normies and the left say but less than stormcels say) to get more shit and fewer consequences while still reaping the beneftis of this.
However, the left's "interest group" framework (AKA "intersectionality") ignites the "fury" of anyone excluded from their framework- "cis straight white men", for the most part- causing them to form their own knee-jerk "reactionary" political faction (this is called "the right"). "The right" basically just defends "muh tradition", the shit that, while sure it created a stable and functional civilization, it also created a hellish, miserable, stifling environment. "The right", to "own the libs", supports an emphasis on "muh tradition" "muh country" "muh flag" "muh race" to punish the weak, unjustly and unfairly, by making fun of the left without actually acknowledging any of the left's genuine concerns. The right simply "reacts" by supporting the restoration of past societies at some nostalgic point, ignoring that most of those periods they fetishize were just as bad, just in different ways.
Being a "GigaChad" warrior in the army and getting to gangrape sometimes before getting slaughtered before age 25 but getting to rape when you aren't killed by wound + infection first, contrary to right-wing opinion, isn't actually any better for incel men than getting all the material luxury they could ever want and sex robots and all kinds of one-in-a-million capitalist loopholes where we COULD strike it rich but probably won't and will remain lonely, but have unlimited copes.
Having all the women taken by a religious right-wing harem warlord explicitly where rape is good and normalized isn't any better for incel men than having all the women taken implicitly by a ridiculously complex system of technological removal from reality by Chad and other systems like we have now. Either way, the result is the same- most men die sexless and miserable.
Stormcels also usually display incredible ignorance of how the past actually worked, romanticizing the past just like the left romanticizes the future.
You can't be based and either right-wing or left-wing. You have to reject the whole framework, go scorched Earth, and start anew.