Just to be clear, it didn't call itself the "alt-right" back then. GamerGate was a turning point, I think. And yeah, it hit mainstream in the 2016 US presidential cycle. But until maybe 2015, I really had no clue that this was a political thing.
Somewhat off-topic but I appreciated the combination of your analysis, mirimir's response, and your admittance that the initial analysis was not altogether correct. Especially online, it's rare to see people admit that they're wrong especially in the face of a (presumably) factually based reply.