The United States of America is literally shit when it comes to a mathematics education. Literally fucking garbage.
It strikes me that these types have a very "essentialist" view of learning. That the earlier you learn something, the more essential and fundamentally true it is because "even KIDS know that!" Higher levels of education aren't viewed as a nuanced revision of more basic knowledge, but as stuff that builds on and always doubles down on the absolute truth of what was taught earlier. So nuance is seen to them as "confusion" about stuff they've "understood" since they were kids.