You say majority of antifa is peacefull, and where are this majority publically condemning the act? Because from your post I could infer that the minority (beeing you) is peaceful and condemn the act.
That even goes to other people saying they do all ruckus and go unchecked and even defended by politicians... and these are defending the violent acts not the Idea of antifacism.
Biggest problem would be that the majority of Antifa never gets asked. I can only provide anecdotal evidence, but I know just two people who actually think violence is a legit tool for Antifa to use (although to my knowledge, they didn't ever use violence). I can't count the number of people who think otherwise. Antifa also can't publicly condemn the act, because as I said, it's not an organization. There is no spokesperson or whatever who can speak for Antifa. You can only speak for yourself and you're just a part of it. So if some asshole on TV defends this kinda shit, he's not talking for me or my buddies, he's just talking for himself.
I'll be perfectly honest with you, I don't follow the news about Antifa all that much, so I haven't heard of anyone defending those kinda actions. If that happens, that's not ok. But you still shouldn't project that to the whole movement. But just out of curiosity, who is defending such actions?
Official member of VGC's Nintendo family, approved by the one and only RolStoppable. I feel honored.