Are Americans generally aware of how poor their chocolate is perceived outside of North America?
Obviously many US firms are well-established as global leaders, Mars alone is significant enough, and what they make in other markets and for other markets is different but if you generally talk about "American chocolate" in Europe, many people who know it or have tried it will wretch in repulsion.
Yes, but with a dash of no. What and which chocolate is being compared?
If just the commercially-available $1-2 candy bars, then they're going to be substandard. I'm guessing that's probably all of the additives and preservatives to keep it shelf stable for longer periods of time, and the stretching of ingredients with fillers to keep the costs down. I wonder if it's because of our litigious society, or even a modern expectation that all packaged, non-fresh food (i.e. produce) has a shelf life of usually 12 months from production.
I've tasted many different imported "cheap snack" chocolates and they're honestly not much better or worse. One example I'll use are Kit-Kats...we love them in our household. I've brought home examples from Canada, Trinidad, and some imported from Japan. While there's a very slight difference in the consistency of the milk chocolate, I honestly can't tell a huge difference between the examples. I can notice a mellower, less-acidic hint in the chocolate of Canadian Kit-Kats, but I probably wouldn't notice the difference in a blind taste test.
It took until I was thirty to appreciate dark chocolates (though >90% cacao is just chalk) so I wouldn't say my tastes are entirely refined. They're best enjoyed in slow doses, which seemed to be the mistake I'd made for years. But I also think: (A) we've allowed more additives to most foods over the years which has some variations in quality (B) people are nostalgic and think all food should taste like the first magical time in which they fell in love with that particular delicacy.
I do prefer most of my cheap chocolates chilled, seems to taste better, in my (and my wife's) opinion. I'll occasionally splurge on the finer stuff but like most technical arts, the differences are rarely noticeable after a price point over 2-4x the least-expensive option, with gains-to-price being on the asymptotic side of the logarithmic curve.
¯\-(ツ)-/¯ Could be just me.