The relationship of many American leftists to patriotism reminds me a lot of those guys who grow up in oppressively evangelical communities and decide to express their disillusionment with it by becoming black metal satanists - a oppositional mirror of Christianity - instead of becoming atheists.
Like the correct response to the realization that nationalism is a false consciousness used to suppress class conflict is to focus on raising class consciousness not to root against the nation everyone around you is rooting for.
Flag burning anti-patriotism is stupid in the exact same way that jingoistic chauvinism is stupid but it's also stupid in an additional self-defeating way because it sets your goals up in opposition to a bunch of symbols and institutions that normies have been trained their whole life to believe in.
Sounds like we need to find popular symbols that aren't also deeply associated with oppression, bigotry and feudalism... Like some sort of combo Beyonce/Taylor Swift flag!