Yes, I agree there is a basis for defensiveness, because you so often are being attacked. And I'll concede I'm defensive about the left shooting down Dems harder than they do Republicans and helping Republicans win and ultimately hurting the people they're fighting for.
We're critical because we want to win. Biden is the only one to have RUN on centrism and won, and that's because he followed Trump and his absolutely catastrophic COVID situation. Harris LOST to Trump on the centrist platform. Obama ran on Hope and Change, and ran to the LEFT of where he went.