No, they aren't accepting it in every other city or state.
The Portland Frog became a national icon when a ICE pepper sprayed straight into a costumed protestor's air vent. I believe that the use of whistles to alert the community was pioneered in Chicago. And now ICE are in Maine so the locals have turned out in force. There will be plenty more examples across the US that didn't make the national headlines.
Neither Walz or Frey have incited anything. Frey's speeches have explicitly called for calm. The Trump administration sent thousands of agents into Minnesota (remember, a state a long way from the Mexican border with almost no undocumented migrants) specifically to inflame tensions. It helps Trump at the mid terms if he can reduce turnout by intimidating people in swing states. And then Noem, Bovino, Bondi etc. have poured fuel onto the flames by slandering the victims with outrageously transparent lies.
Nor are there "agitators" on the ground. At least not on the side you claim. The only agitators are the likes of Jake Lang, the racist who turned up to cause trouble by ranting about Muslims through his microphone. He didn't get beaten up though, he just got silly-stringed and water-ballooned.
Alex didn't set out to go to a protest. This wasn't an organised demo or whatever, this happened spontaneously when ICE turned up. It's pretty unremarkable for an American in an open-carry state to be in possession of a firearm.
ICE wouldn't have issues doing their job if they were actually doing their job (rather than being sent en masse to opposition cities to cause trouble) and doing it legally. In a civilised country, people have rights to protect them from government overreach. The US used to claim to be such a country.