The US is itself a huge market with relatively uniformity (you mention the address information as one example, the currency is another). I don't see anything wrong with a US company deciding that US customers are reasonable target. Yes, they are missing out on business, but they are also missing out on hassles with deal with the RotW.
So my take is that for many US companies the answer is "Why bother? We have a big market here".
So my take is that for many US companies the answer is "Why bother? We have a big market here".