Yes, Mr. Gladwell comes on strong with the "we seem to have forgotten what activism is" argument. Still the article does a fine job of pinpointing the real value of social networks. That social networks are loose links and are great at creating communities. But if you want to bring that community to action then you need stronger links with clear direction, purpose and leadership, something social networks aren't built to do.
This goes back to an argument I've used many times, decide what you want to do first, then pick the technology that will support it. In other words, communication can be loose or specific, and some ways of communicating are more effective at bringing a group to action over others. The fact that there are new forms of communication does not exclude other forms. The article quotes historian Robert Darnton:
"The marvels of communication technology in the present have produced a false consciousness about the past—even a sense that communication has no history, or had nothing of importance to consider before the days of television and the Internet.”
In my mind this is really accurate and it sets up Mr. Gladwells premise: That there are many forms of communication that hold importance for what it can do for us. Confusing the ability to network more effectively with activism is doing both activism and social networks a disservice. Both have great value in this world but they are not the same thing.
Twitter, Facebook, and social activism : The New Yorker