You mean the fake bullshit lying kind of antisemitism.

Israelis are nuclear armed Nazis.

Tact occurs in the absence of maturity, so immaturity is certainly adjacent to your superior term.

And it’s not so much about the person breaking out a soapbox, but more along the lines of breaking out a soapbox in a venue that is neither theirs nor public, especially when they are a contracted rep of that venue. That person was there on contract to entertain the patrons according to a clearly-defined program. That alone means they don’t air anything beyond what is defined in that program. It’s exceptionally rude to the patrons, who came there to see the program, not the person (specifically) or their protest.

Things get blurrier when the artist is the focus of the program, like when a band is playing, and they - as a group - pull out the soapbox. There I see a point in their favour, as patrons came to see them, specifically and exclusively, perform.

Even supporting artists have more of a leg up than this guy, because people will pay money to see a specific band even if it’s only an opener.

My first thought is What if it was a flag representing some group I disagreed with? How would I feel then. If your support changes based on which flag then your support isn't valid. Now if he had gone out on the street right after the performance and waved his flag as viewers were leaving the property, I'd say he every right and MGMT could fuck off. But on the stage at the end of the performance, it wasn't his right to do so.

False equivalence - MAGA is a party in the US that is the oppressor. Palestine is a country and people that are oppressed and genocided.

Sure, yeah, protest, but this is the expected result is the point. Protest doesn't mean there are no consequences. That's my point. This was still a good thing the perform did. It'd be great if there weren't consequences, or at least less severe, but it's pretty expected.