The alt-right as CNN sees isn't an invention, but it's a use of a tool. As mentioned before, to be cruel to a people, to be neonazis to a group of people only requires calling the group neonazis.
However, that post is probably closer to the truth than anyone else on neogaf could muster up. The alt-right is small and the white nationalist part is even smaller. The press doesn't want to do a report on trolling and post-irony that exhibits any effort in understanding the subject so it's easier to just wash that part away and focus on a Richard Spencer. If they did delve into the true nature of the net and post-irony then they'd have to walk back a great many other things they lied about in the past, such as Gamergate.