It's become almost a cliché nowadays for people on the political far-left to distance themselves from the online social justice movements. The one aspect about these people (such as those on tumblr) that I've come to notice is how little they truly understand about what needs to be done beyond the keyboard, and how much that relates to how little they understand about hegemony and ideology. It's actually quite easy to see how those pejoratively labeled as "social justice warriors" apprehend, to some extent, how institutions like the media manipulate individuals into thinking in certain ways, or how everyday language has consequences in regards to how we see and treat each other. However, when it comes to going beyond the now cliched calls for "privilege checking", there is no real motivation to orchestrate any kind of political praxis that would take to challenging the cultural logic of modern society.
There are a few ways to approach this issue. One tends to be the understanding held by the more "authoritarian" (if you will) people on the Left. That is, the typical theories relating to base-superstructure, that the function of specific institutions corresponds to the mode of production - albeit with some relative autonomy, and that ideology is shaped not only by a few individuals on the top but by the institutions that make up the superstructure. Within this, there is the notion that these institutions must be seized as part of a larger program; we see this, for example, in the "historical bloc" or "power bloc" and how Gramsci's Modern Prince (communist organization) must seek to grasp the minds of the people through intellectual reforms. These theorists understand that these ideological apparatuses mold individuals into subjects, and they have zero qualms about doing the molding.
Even as an anarchist who has no love for authoritarian socialisms, I can appreciate this view, since it enables a practice to arise from its theory. This may come off as a form of brainwashing, but we can look at the culture that's present today and understand how much of it furthers capitalist relations of production. In fact, we can look at plenty of revolutionary societies and see the efforts taken to remold the superstructure as well as the base. Even something like the creation of a Temporary Autonomous Zone fits with the emergence of a new paradigm, because even though you aren't seizing institutions, you are creating a challenge for them.
On the other hand, there is this specific attitude which assumes these institutions are just what they are and that there is no need to direct or upset them. The idea is, we're just going to stay on the sidelines and let the capitalist media, schools, religious institutions, and such do what they do. But as soon as someone does something that does not fit our preconceived notions of what we would see them as being in a just society, we're going to shame them until they become so humiliated that they have no other option but to submit to us. Of course, in this scenario there is nothing of an attempt to go beyond the relationships between single individuals. There is no program, there is no organization, nor is there any kind of challenge to the dominant ideology by any means.
This is the real problem with social justice liberals: they allow for themselves to be pacified up until something "problematic" occurs, and then they start rabidly shaming until the issue is forgotten along with their anger. They refuse to learn what Gramsci knew, what the Bolsheviks knew, and what the Spanish Anarchists (to an extent) knew: the superstructure forms and reproduces the base, and thus, like the base, needs to be dealt with on a systematic level. Without that, you're forced to resort to extreme individualism where everything is handled on an individual basis; even then, there is a reluctance to grab people's minds and benevolently direct them somewhere better ("it's not my job to educate you," etc.). And by that time, you're not engaging in any sort of activism. You are engaging in petty ramblings that do nothing but reassure your ego.
Now, the social justice crowd tends to look at this in a very black-and-white manner: "Oh, well if we organize or fuck with the system then we become elitist and authoritarian!" But then comes the great irony: when any part of the culture goes against their moral sensibilities they start viciously shaming in a manner that could very well be looked at as a precursor to an even greater authoritarian attitude.
Tumblr Social Justice would rather remain consumerist and pacified. They may find redemption in their consumer choices, be it Beyoncé's latest album or a "fair trade" T-shirt. They may rely entirely on simulated activism behind their computer screens (and let it be known that simulation entails that solidarity does not exist). They may also be unwilling to take matters into their own hands and get socially active in the real world so that the world is shaped in the way they want it to be. Then, when someone or something in the culture goes against their values, they become nasty and vicious in response, only to default right back to their forgetful, pacified selves. You ask them: "So, how do we organize around said issue?", and they tell you: "We can't do anything, we don't want to look bad, we don't want to be disturbed from our everyday lives. We're only going to shame our peers whenever they commit a 'microaggression'. We don't want to look like elitists, white saviors, or extremists like you."
And then you are the extremist, because you've remembered the struggles of the past and have the motivation to uproot a disgusting system, when they're content with updating their Tumblr blogs in the name of "awareness"!