Hitler worshiping neo-nazis have been around since George Lincoln Rockwell. They have accomplished absolutely nothing besides acting as a cartoonish freakshow that the enemies of the white race have successfully used to demonize any advocacy for white interests or assertion of white identity. The alt-right, if anything, has arisen despite this.
The rise of the alt-right, as I see it, can be attributed to a few things:
The boiled frog of demographic change has made whites more racially conscious and nervous about the future. The left has gone full-retard with blatant anti-white racism, by their own standards, and its obsession with ridiculous issues, like having 57 genders or sex change therapy for 10 year olds is easily mockable and repulsive to a large contingent of the population. The explosion of the internet has caused the media and academia to lose narrative control and the left's internal contradictions are collapsing on themselves when exposed to the light of day. Because of political and financial pressures weighing down on them, both major parties are totally delusional, corrupt, and unable to honestly address issues that people care about in a realistic way. The alt-right has stepped into this vacuum by providing insightful commentary and a compelling alternative interpretation, especially to whites who feel besieged in their own countries. P.C taboos have mentally handicapped political discourse, so the alt-right is one of the only groups contemporarily capable of examining societal trends intelligently and honestly. Trolling may have it's (limited) place, but the idea that the alt-right's rise is due to puerile bigotry, Hitler worship, or a singular obsession with creating white ethnostates, is just wrong. In fact, reliance on the above is a sure road to failure.