I don’t think reCAPTCHA was designed to reinforce American culture. I think it was simply designed to make ML training sets for their other projects, and they neglected to make it accessible.
I don't know much about the history of these tests. Can Hanlon's razor principle be applied here?
No. Look up to so called "literacy tests" used to disenfranchise voters. The people who designed those tests, and the "IQ" tests knew exactly what they were doing.
Similarly, https://arxiv.org/abs/1110.1556 - the "Jewish Problems" that were extra-hard maths questions used to find an excuse to prevent certain students from getting into university.