Such could be used as a legitimisation for more state violence & anti-terrorist measures and could lead to a more authoritarian state, helping the profiteers of such a society model even further. A conservative or even facist revolution could always be the consequence of a failed emancipatory revolution. Luckily the US isn't as oppressive as it gets (at least toward a big part of their own citizens) and there is a chance for social movements to emerge and express themselves and hopefully have an impact. I would understand if you said the reformist approach has never led to a satisfactory outcome - slavery and later racial segregation was abolished far too late and the ancestors of the victims still have to carry the burden. But which revolution that included overthrowing anything violently has ever led to a freer society? If there actually were militant rebel groups trying to overthrow the US government they would be crushed by superior military forces & state surveillance & authoritarianism would increase. Sure, you can dress up like a Guerilla fighter and do some cosplay protesting if you're into it but that's hardly revolutionary. Reformist demonstrations are always better. Transform the beast if you can't kill it (you can't)
What are more useful terms to understand social tensions and inequality?
More than lefties I feel right-wingers often have issues with their masculinity or a twisted sense of masculinity and like to engage in respective poser activities. Watchin' the game, killing a wild animal, involving in fist fights, having and aggressively defending some poorly thought out political stance, anything that makes them seem stronger and more "manly", lol. Of course there are more mature people on both ends of the spectrum but lots of people use politics as some means for identification or expression of their feelings rather than trying to understand how legislature impacts coexistence
There are no pure systems. Capitalism and communism aren't antonyms either, they are umbrella terms for lots of different models for analysing (or diagnosing) existing societies or creating visions for societal development. Every successful democracy existing in a capitalist economic sphere has socialist & even communist elements and all states that identify as socialist or communist do capitalism. I guess the Cold War has clouded our understanding of these terms, so maybe you are right in that they aren't that useful anymore & shouldn't be used as basis for some dogmatic state ideology