You label them a terrorist organization then they will just change their name and keep on doing what they do. Why not try and understand where the problem is coming from instead of just putting labels on everyone? Violence is wrong but Antifa sure as hell isnt the only group being violent out there.
You are correct in that they aren't the only violent group, but the problem is that violence and intimidation is literally the ONLY way they demonstrate.
They either riot (a la UC Berkeley) or show up to other protests to try to stir up problems, and if that fails, they will just start throwing fists at people to try to provoke them. This "punch a national socialist/Bash the fash" nonsense has really gone too far.
It isn't that I don't have sympathy for the gullible people that get sucked into Antifa-esque nonsense. I have a ton of sympathy for those people. I know a couple of them- if the pattern holds true, they tend to be sheltered and believe they are going out to protest some injustice or advocate for minority rights or something along those lines.
The problem comes when the group shamelessly preys on the weak (the sheltered, the mentally ill, and the misfits looking for belonging) to recruit them for their cause, and painting your opposition as "fascists" and "national socialists" is an incredibly dangerous thing to do, as it dehumanizes them by painting them as these historical "boogeymen."
Look, it tears me up inside because a good friend of mine from High School is all caught up in the whole "revolutionary left" stuff and I know she's smarter than that, she's just very naieve and trusting and has struggled with lack of belonging/mental illness for a while, and she believes that she is doing the right thing by going out with Antifa and "fighting for the cause." She's 100 lbs soaking wet and probably couldn't even bench the bar with no weights on it. The fact that these vulnerable people are being manipulated into being violent really sickens me.
I have so much sympathy for these clearly vulnerable people, but I don't believe in allowing them to be violent without repercussions. If one swings at me, I wouldn't hesitate to defend myself, but I don't believe in attacking people for their politics. I don't care who it is, violence in the political process is unacceptable and Antifa is taking advantage of society's most vulnerable people.