For the left, patriotism means loyalty to their policy agenda; you’re “unpatriotic” if you don’t want to give them more money.
The left thinks traditional patriotism means respect and loyalty for a horribly tainted past filled with “isms” – racism, sexism, etc.
When people who have serious disagreements and strong complaints against current government policies stand together in respect for the flag and anthem, they are saying: “We are brothers and sisters despite all this, and I love those I oppose.” That’s poison to collectivists.
Traditional displays of patriotism unite reverence for the past, brotherhood in the present, and confidence in the future.
We should have contempt for the view that patriotism means loyalty to policy agendas and our differences are what define us.