It's a good essay. My takeaway is not that it's blaming the alt-right (or 4chan) for Trump, but explaining why both Trump and his support from those groups are *symptoms* of what's wrong with America. This is the same conclusion the author reaches:
Moving forward, the problems are many:
The Establishment (Dem or otherwise), while preferable to Trump, also still fails at solving America's underlying problems.
Trump's victory may empower his cultists and other followers. And make no mistake, they all representing a worsening of an already bad situation.
I don't know if there are good solutions to the problems that created Trump and his cult, or to the problems they themselves represent. I'm starting to think we only have a choice of bad solutions. (Flight, violence and/or loss of democracy, collapse.)