"Unite the Right" says it all: it was meant to attract a wide range of people who share a loose affiliation of being "on the Right" and wanting to keep the statues, but most likely not all were extremists or "white nationalists" or "neo-Nazis".  Because they were attacked by Antifa, it is the extremists that got the attention they craved.

But the organisers of the "Women's March" were extremists like Linda Sarsour, who assembled women of all political persuasions under the same anti-Trump banner. Not many bothered to investigate who the organisers were, and no one bothered denouncing them as extremists:

https://www.nytimes.com/2017/08/01/opinion/womens-march-progressives-hate.html?_r=0