That leftists were wrong to force their propaganda, clever and logically superior as it might appear, upon the masses who wisely stuck to conservatism since forever and understood conservative wisdom on a gut level? Yeah, yeah, you'd say that it's just as bad or worse than the modern "thoughtcrime" currents I mentioned - but I think there is a significant difference.
For the last 200 years, lots of revolutionary/populist left-wing movements, even non-Marxist ones (incl. ultimately triumphant ones like 1st/2nd-wave feminism or abolitionism), have been using variations on class consciousness as a theoretical foundation for their agitation and rabble-rousing. And at least their official descriptions of "consciousness-raising" have been much like what I mean - and what I assume Zizek means - by "articulating the unknown knowns".
Of course, reality is messy and politics fucks shit up, but ultimately I feel that the idea of consciousness-raising is not a clever trick, a deception of the masses who know better but are led astray. In the right hands it can serve as social psychoanalysis of sorts, to resolve deep-seated exploitation and oppression by dragging them from the collective unconscious into the light. A good example is how Western countries are practically at the end of homophobia. It was first systematically opposed by the Left's critical theory and Freudo-Marxism; now it's vanishing even on the right. Of course, there have been failures, which naturally resound louder - such as the reckless politics of "national liberation" leading to rivers of blood and zero liberty in the decolonized countries.
But here, before you say: "Aha, so you admit that this radical meddling is irresponsible and unaccountable!", I'd ask you to consider, what if the masses have always had a desire for emancipation, what if the ideas of left intellectuals could never have been so transformative without a mute but powerful demand for them?
Every revolution has a fundamentally real reason! It might not even be a "good" reason - see the "men's rights movement" and their politics of bitterness - but a revolutionary trend cannot be kicked off with simply propaganda, mass psychosis or shallow moral fashion! This reason can stay deep and strong under a calm surface, dormant for ages. Slaves did have fundamental overwhelming discontent about their position in America; women did have fundamental overwhelming discontent about their position before feminism. This fundamental psychosocial reality of oppression is what the oft-derided Marxist Historical Materialism is clear-headed about, and what can lead a right-wing thinker to denial (e.g. Moldbug on the Russian revolution) or biting bullets (e.g. Chesterton on the French one).
And, like Gramsci said, the oppressed masses can and do generate their own intellectuals who are driven to become a voice for the voiceless - by their origins, not by whim or ethical abstractions. Who taught racial equality or feminism to Frederick Douglass, an escaped slave (who must've simply got a jackpot in the genetic lottery)? Evil power-hungry Northern abolitionists?
No, it must be the same process by which a black PUA-practicing guy commenting on a men's issues blog can realize how his struggle is very similar to that of women, despite all the public hostility between feminists and PUAs. When he articulates the prejudice and oppression that have been a personal concern in his life, he can't help but notice that other groups face very similar oppression. Grassroots leftism!
You ever notice that the most strident voices about “The decline of Western civilization” and supporters of the “Send their asses back to the kitchen” type of rhetoric are mainly white males between the ages of 30-50? [Censored], [censored], [censored], just to name a few...
As a black man anytime I hear things about how women should know their place, or that society is being ruined by women taking an active role in society, you know what I do? Take the word “women” out and insert “blacks”, or nowadays in SoCal where I live “Mexicans”. See where I’m going? They talk about the “good old days”. What good old days? Good for who? White men between 30 and 50? Why would I be interested in going back to the 50s? Or 30s? Or mid 1800s? Who does that benefit?
P.S.: Konkvistador asked if Nazism could count as a catastrophic and evil consequence of this sort of thing. The communist terror in China could, I think - but not Nazism. The Nazis killed and enslaved people under a wholly illusory cover of fighting an arbitrary Other. Their violence was not directed at the real social system.
A more compelling example of a social revolution causing catastrophic evil things would be the Red Terror and the Cultural Revolution in China. It was indeed mostly driven from below with encouragement from Mao; it was a part of sweeping systemic changes; it concluded decades of chaos and strife, and centuries of misery and exploitation; this still doesn't justify an orgy of slaughter and cannibalism. I don't know in what way to talk about it.
You're still talking in terms of classes that shouldn't exist. I don't care about blacks, or women, or white males between 30-50. I think anyone "taking an active role in society" who doesn't own land or a business has horrible consequences. I say this only to point out that your argument sounds like nesting dolls and some of us do bite the bullet and wish to unravel down to the base case.
And I think meritocracy is actively resisted by those who face the reality that in a society dominated by technology white/jewish/asian males currently have a huge advantage, regardless of whether that advantage is genetic/cultural/path dependent/oppression based.
As Multiheaded added, "Personal is Political" stuff like gender relations, etc also may belong here.