That is not my experience at all. Most Americans get extremely defensive when someone criticizes the US, even people who know better. Many are ok with specific criticism (like, healthcare sucking), but it doesn’t take much for them to revert to 'murican mode.
I have been living in the US for over a decade and been to 2/3rds of the states.
Are you in tech or some other field that doesn’t involve interacting with different socioeconomic groups?
Most of not all states guarantee some “interesting” encounters if you leave the cities. In California I have seen Confederate flags flying, met neonazis, and plenty of Trump supporters. Trump got over 34% of the vote in California, almost 39% in Washington and over 40% in Oregon. Those percentages are not a majority, but I think it sets a floor, since Trump supporters are not exactly trash talking the US.
I have spent a lot of time doing canvassing and other activities that mean I encounter people with very different ideas, so that would definitely explain the different experience.