Americans are extremely polite with lots of yes, sir, thank you, excuse me and refuse confrontation with those who visibly disagree with them and won't be changing their minds. It's part of the feel good politically correct culture a few generations have grown up with. There is also a greater difference between what Americans say and do than in other cultures. Most Americans don't have a "protest/strike" culture that exists in other places. In fact, they are taught that it is rude to cause conflict.
Of course, you can find examples contradicting everything I say.
Life is not a dress rehearsal.
Most Americans never leave the country, or at least never go beyond North America. There are many, many people here who are afraid to travel to a non-English speaking country, because they fear that they won't be able to communicate properly, and thus might end up saying something that offends the local people.
On the other hand, the Americans who do travel abroad tend to be more self-confident, either because they do know the language of the place they're visiting, or because they just figure that everyone they meet will speak English (and at a fast, conversational level). It's the latter group that often gets into trouble and hurts our reputation abroad.
If you look like your avatar-photo I surely woud avoid making offensive remarks about Americans and be especially polite when talking about Texans.
But there are ugly-*nationality of choice" everywhere. The real problem is probably that the USA and its politics has such an impact almost everywhere on this planet and there are so many idiots who believe they are entitled to hold every single American they meet on their way responsible for everything ...
... just like there are idiots who think they can hold every German responsible for things that happened two or three generations ago.
Most travellers I have noticed try to stay diplomatic and not escalate things, when they meet such people.
(Did they use a defibrilator to reanimate this thread?)
I have to agree with your post. Most people are polite and understand that you should always treat people as an individual and not engage in stereotypes and bigotry. It goes against our human nature but we must try.
I have met so many wonderful people from other countries. It would have been a pity to alienate them with holding them personally responsible for things done by politicians.