My very unscientific feeling: The constant influx of pieces like this since the election feels like the mainstream media redirecting calls of "echo chamber" elsewhere.
Yeah, I don't think it's invalid to say that fake news is a serious problem (or even that it probably helped elect Trump), but I think there's a much deeper crisis of news, bias, and the nature of truth in the Internet age that needs to be addressed head-on.
An echo chamber compared to what, though? Twitter's alt-right? They're not exactly honestly measuring the material problems of rural Americans: they're passing memes around about expelling the Muslims and gassing the Jews.