The knockout game phenomenon really, really makes the Establishment uncomfortable. Although it took several years, the seemingly senseless savagery it displayed finally forced the knockout game from being a subject covered almost exclusively by the alternative right to something the mainstream media found increasingly difficult to ignore. Sure, Fox News still does ten minute segments on it without once mentioning race, but at least they're raising awareness. That counts for something!
Four major reasons why the knockout game causes Establishment pontiffs such anxiety:
1) It validates the Derb's non-black version of "The Talk". Be weary around blacks who are unknown to you, especially when they outnumber your group, especially especially if you're a female or a man aged 40+, and especially especially especially if you're alone.
2) It makes a mockery of the mendacious hate crime Narrative the Establishment perpetually pushes. It's as familiar as it is diametrically opposed to reality--the Trayvon Martin/George Zimmerman saga being the most recent highly visible illustration, but it's pervasive presence can be detected in virtually every case in which putative irrational -isms are involved.
Instead, the knockout game displays the reality of interracial crime--it is an overwhelmingly black-on-white affair, with blacks nearly 40 times more likely to commit violent crimes against whites than viceversa. Blacks are even significantly more likely to be convicted of federally designated hate crimes than whites are (and that "white" number includes relatively more criminally prone Hispanics).
3) Relatedly, the knockout game reveals that one of the left's favorite tropes--that crime is an unfortunate but essentially unavoidable consequence of poverty--is bullshit. Correlation isn't causation, heh. The game's perpetrators aren't acting out of desperation, they're not stealing anything, and they're not enjoying any material gain from their vicious assaults--instead, they're acting out of a mix of boredom (poor people have a lot of free time on their hands), social posturing, racial animosity, and animalistic impulsivity.
4) It is about the most effective argument in favor of gun rights imaginable. The police can't protect potential victims from knockouts and contemporary American communities won't organically protect their fellow citizens, either. Only you can prevent knockouts, and the surest way of preventing them (or second surest--see item #1) is by packing heat.