>>34186
I agree. The most popular cut-off event I've heard is September 11th, 2001. Before that it would have been the Soviet Union's fall, then maybe the end of WWII? Or maybe WWI since it represented the end of the Long 19th century.
>>34263
I'd say /pol/ started getting popular after 2008. The theory that makes most sense to me is the the switch from a Republican to a Democratic US President inverted what exactly being an edgy freethinker meant. Imageboards have a contrarian strain to them, it'll be interesting to see if the possible upcoming Trump administration changes the popular opinions here.