Have any of the people casting aspersions against the USA (as a whole) ever lived there? I have - and no, I am not a US citizen. While I don't necessarily like everything about the US (heck, I don't necessarily like everything about my own country) I like "Americans" in general.
Bureaucrats, on the other hand, are a different thing. If you met some of these people at the mall or in a coffee shop, you'd probably like them. When they're on the job, it's usually their senior management who determine the overall attitude. I've recently had very pleasant border/airport experiences, neutral experiences (professional and courteous, neither pleasant nor unpleasant) and bad experiences. I don't paint all of the US with the bad experience brush. This may be a case of overzealous workers, or it may be a case of two tourists who tweeted silly things and then didn't handle the questioning about it well and dug themselves in deeper.
Recently I was talking with an American who had a bad experience visiting Canada. He was speaking at an Anti-Money Laundering and Counter Terrorist Finance conference. He was over tired when he got to customs and said he was there for a money laundering conference. It went downhill from there and he was detained for 2 hours because he got angry and defensive and the customs people dug their heels in too.
The average American I've dealt with has been nice. Yes, they are raised with the sense that their country is the greatest in all of time, and maybe they have a hard time believing that not everyone else in the world wants to be American, but so what. Maybe some of them are arrogant. So what. I've met people from other countries who are arrogant and think where they come from is greater than any other place. There may have been times that I have come across as arrogant about my homeland.
Please, don't write off the USA just yet. Yes, they are in a world of hurt. Is Greece doing better? How about Italy? Our whole world is troubled, and every one of our countries has plenty of its own problems. One ridiculous instance of tourists being turned back doesn't mean US society has collapsed.
Also, don't confuse a country's government and its actions for the regular people of that country. Way too often there is a vast disconnect between the two. Politicians and bureaucrats too often seem to think they know best and make decisions in that vacuum.
Now, I need to go wave my country;s flag around for a bit. ;^)