> you already think we are odious
I had to look up the word to double-check as a non-native English speaker. A quick definition I'm working with is "Arousing or meriting strong dislike, aversion, or intense displeasure." The synonyms assumed are: evil, cruel, hostile, nasty, wicked (all from Grammarly).
The experience of "you" - Americans - for non-Americans is shaped by cultural exports, personal contacts, and interactions with available American institutions. The last of these is likely to start with the immigration policy and its execution in the form of an embassy visit to apply for a visa and later with the officers at the airport. How confident are you that these interactions cannot be described as "odious" in a significant percentage (maybe even the majority) of cases? I've never experienced it myself, but in my social circle, almost all who tried were pretty bitter about it, even when successful. There were some outright Kafkaesque situations as well. Does it come as a surprise that a completely ruined "first impression" ended up biasing them to some extent?
I think that's rather expected. I'm pretty sure the same is true for a portion of people who want to visit or immigrate to my country. I can hope it's maybe less prevalent - we're not as sure of our greatness here (still better than those others around, obviously! /s) - but I wouldn't count on it to be an entirely positive experience, either. Admitting this and trying to fix it (including, unfortunately, convincing that dude who had to deal with his fair share of assholes to get here that not everybody is an asshole) would probably be a better course of action than isolationism you seem to favor, but to each their own.