Agree. I've been to 75 countries and virtually everywhere else you get treated better. What you have to know is that the US immigration staff have improved. Twenty years ago I think they sucked lemons for breakfast before they came to work. I generally find the immigration staff ok nowadays, although not particularly friendly. It's the security staff who appear rude.
But you have to understand that US is a relatively authoritative country. Where police or security in places like Australia would politely give instructions, (eg, I'll have to ask you to stand behind the line) - in the USA they bark, "STAND BEHIND THE LINE!" as if you're under arrest. But Americans don't seem to notice it and I think culturally read it as giving clear instructions.
