…it is important to point out that however materialistic [Walter Benjamin’s] approach to history may seem, nothing is farther from Marxism than the stress on invention and technique as the primary cause of historical change. Indeed, it seems to me that such theories (of the kind which regard the steam engine as the cause of the Industrial Revolution, and which have recently have been rehearsed yet again, in streamlined modernistic form, in the works of Marshall McLuhan) function as a substitute for Marxist historiography in the way they offer a feeling of concreteness comparable to economic subject matter, at the same time that they dispense with any consideration of the human factors of classes and of the social organization of production.
–Fredric Jameson, Marxism and Form (1971)
McLuhan-esque media studies as a bad kind of historical materialism, one that precisely leaves out class struggle (in other words, real human beings) as the motor of history. Wish social media boosters and Twitter revolutionaries thought about this, but their bromides go down so well! Until they don’t:
The cruel truth of the emerging networked news environment is that reporters [i.e. workers] are as disempowered as they have ever been, writing more often, under more pressure, with less autonomy, about more trivial things than under the previous monopolistic regime. Indeed, if one were looking for ways to undermine reporters in their work, future-of-news ideas would be a good place to start:
• Remind them, as often as possible, that what they do is nothing special and is basically a commodity.
• Require them to spend a portion of their workday marketing and branding themselves and figuring out their business model.
• Require that they keep in touch with you via Twitter and FB constantly instead of reporting and writing.
• Prematurely bury/trash institutional news organizations.
• Promote a vague faith in volunteerism.
• Describe long-form writing as an affectation or even a form of oppression; that way no one will ever have time to lay out evidence gathered during extensive reporting. Great for crooks, too.
Bad historical materialism: great for crooks, too.
UNFASHIONABLY LATE 
Point taken, but surely you want to keep a McLuhan-esque perspective as well. Twitter, FB, etc help to reinstate a new tribal mentality where chatter predominates and the noise of it makes extended reflection that much less likely. An important factor in the institution of a new type of public consciousness that makes people less inclined to take things like Marxism seriously and less able to stomach the kind of discipline required by the vanguard. And all that regardless of the fate of writers (which is, admittedly, lousy).