Remember when you point a finger, three fingers point back to you. The Antifa group does use violence, but you do you believe the American Nazis or the KKK will sit down and discuss things rationally over a cup of tea? Your dislike of one group while standing up for other groups that practice the same, or similar, methods, shows you're okay with all groups that practice such.
I mentioned this on another post, if you follow my comments here, and see a warning that billionaires around the country are noticing: while their concerns are about income inequality. One item I mentioned was a Nick Hanauer TED talk, https://www.ted.com/talks/nick_hanauer_beware_fellow_plutocrats_the_pitchforks_are_coming and say income inequality is a basis, but right now we are looking at a mass revolt.
I'll extrapolate it even further, all inequality. Two of the groups you mentioned have ideologies that wish to suppress others based on race, religion, or national origin. Antifa is against those fascist ideologies because they prove to be detrimental to society as a whole. People on the right are surprised that the left is willing to resort to violence. Surprise! Years ago, in my book, I point out the importance of turning the other cheek, but eventually, a man runs out of cheeks and gets his ass kicked. The American Nazi party laid low during the civil rights marches during the 50's and 60's because there were too many men in this country that had fought against them in Germany only a few years earlier. Proclaiming yourself as a Nazi during the peace marches would have meant instant death, not from the marchers, but from average citizens. That war ended over 75 years ago, and any failed to learn from it. Those too young to remember it, or even their parents discussing it, still learned from history. We are on the verge of a revolution that makes the French Revolution look like a cake walk. The suppression of ideas is wrong, but it looks as if history will repeat itself.
