I'd say the poster is very much wrong. As you and I know, social has been around long before the networks and the idea of interaction, well that's not going away any time soon. I do think the role will morph further into a communications part of companies working across teams and products (kind of like how you don't just work on the community side of SPF but seem to talk product, content, etc).
This of course relates back to the OP because, one it means a future job, and two it should be an indicator to get involved beyond the tactics. Knowing how to tweet may get you an interview but it won't build a social career... Getting why you tweet, why a company could benefit from it, and why the customer cares, now that's how you work in social and build something.
As for making it into a job... get experience. Not just as a user but running / moderating a community, operating a page, working or becoming a content creator (blogger if you will) and if you aspire for a bigger role, then as an intern. Social roles are like any other job: experience counts. Since they're so visible experience must be as well.
I've run social teams and am considered a social strategist at times so obviously biased here but glad to dive in deeper if it helps...