Perhaps because "antifa" is a pointless and intentionally-vague conservative scapegoat? If you think they see Nazis everywhere, I'd say you're being
deliberately hyperbolic. I mean, I'm sure you have sources for all the individual incidents you've raised. Some of them sound pretty high-profile, so surely they'll be covered by mainstream (and not just conservative) outlets?
It should be easy; even centrist media tends to abhor violence (for good and bad reasons); there aren't many dedicated left-wing outlets that I'm aware of these days really (mostly not in the UK, definitely not in the US, though obviously my German social media ain't up to scratch).
Organizations can be authoritarian scum without being fascists. We've seen plenty of examples, Antifa is a well-known one among many.
The first half of this is good (see how Communism with a capital C, i.e. the state doctrine in the USSR and later, China, isn't actually communism by theory, because, well, dictatorships. The theory doesn't work well if individuals can exploit it, and I'm not familiar with it enough to ever propose a version that
could work), the second half is just really funny. I mean, people are using "antifa" when they mean what, exactly. The classic German network, it's more modern American equivalent, anybody who dresses in black and opposes neo-Nazis and white supremacists? What do people mean when they use this label? Neo-Nazis are pretty self-explanatory. Even white supremacists are (i.e. it's not as simple as just being racist).
Like, there isn't a coherent ideology at work here. It's anti-facism, simply put. There are tons of people that oppose fascism, and this by default makes you anti-fascist on that axis alone. There are individual groups who use specific tactics, or whom are based primarily in certain countries, but "antifa" is being used as some kind of weird catchall when it's anything but. It's a dangerously loose grouping that if weaponised could see people arrested for literally, well, opposing neo-Nazis.
If you think I'm being hyperbolic, the US is currently in a rightwing swing; Republicans run the show (however well, vs. however well-organised opposition, both are asides for the point I'm making). If a label as generic as "antifa" can be labelled terrorist, and anyone even has the most passing familiarity with what powers that grants government agents, Republicans will only look to strengthen those kinds of powers and escalate punishment (see: restarting federal executions). By justifying anti-terrorist actions against something this vaguely-defined, you open it up to be used similarly against other such loose groupings. It also demonstrates an incredible lack of reading on what anti-fascist behaviour actually
is. It doesn't have to be violent, and mostly isn't. Black bloc tactics are
tactics, and not used solely by anti-fascist activists.