Radical free speech is important and a cornerstone of the US. Yeah, you've got some real shitheads on voat but also a lot of decent people that just don't hold the previously approved PC opinions. The internet was way better before it began to coalesce into megacorps like google, fb, and reddit. Instead of defending free speech they caved to advertisers. The issue w/ that is someone is always pissed off by something and the smallest groups shout the loudest. Now we've got a situation that's gotten out of hand and even regular conservatives are targeted. Voat is basically a concentration camp for free speech online. They've rounded up all the "wrongthinkers" and sent them to one place.
Before reddit and that Mountain Dew (the hitler did nothing wrong naming contest) troll happened /pol/ was libertarian more or less believe it or not. The PC left is Frankenstein and Voat's their monster. Assholes were fewer and farther between online before they all got shipped to the same place.
When you start inventing shit like "micro aggressions" and telling everyone their racist nonstop... I could provide a thousand other examples. The left has even managed to bring back segregation on college campuses only this time they're called "safe spaces" and black only dorms.
The Radical Left and the Far Right are every bit as bad as each other and more alike than they are different. They both have a need to be authoritarian in order to stay in power. (Horseshoe Theory)
Reddit, Facebook, Youtube, Twitter, etc. have no shortage of racists. They've just got the "right kind" in our weird double-standard culture.
This might change overtime as the overton window (what is socially acceptable to say) changes. It will also influence whom they vote for and what they'll teach their children in the privacy of their home.
Donald trump certainly didn't get elected because of positive mainstream media coverage, I think it's fair to say that it was the internet that elected him. If the internet, and it was mostly limited to a handful of communities partially quarantined from the rest of the internet, can elect a president despite non-stop negative media coverage, it probably matters a lot.
Also almost every major political movement started as a fringe group, including the political correct movement that was made fun of by monty python 50 years ago and no one really took serious. Or Christianity. Or the Nazis, who went from 2.5% to >40% in less than 5 years.
http://histoire.museeholocauste.ca/data/timelines/gen/images/large/Chart_NaziPartyRise_ENG.jpg
We might be one financial depression away from the alt-right becoming a mainstream movement.