citation?
Education is a complex matter. There are many people with OPINIONS on what the best way to teach is. These ideas are in conflict and only rarely does anyone study what really works. (rarely compared to the number of opinions - there could be a lot of studies that nobody knows about when they state their opinion)
Humans have a limited lifetime: you cannot teach all possible useful knowledge/skills in a lifetime. I limited this to useful, there is a lot of useless things that are fun to know anyway, somehow those are are interested need time to learn it for fun. I didn't define useful either: is Music/French/Algebra/Sports... useful (I can make either argument for any subject)
Why is reading a classic American author important? Reading is important in an abstract sense, but if you can understand written instructions it doesn't matter what you happened to read to get that skill.
Likewise, what is wrong with using M&Ms for learning math? a concrete example helps to learn. (to be clear, this is an opinion that I was ranting against in the first paragraph - I don't know if I agree with the opinion but I understand it enough to repeat it)
One constant in the US in popular culture is our education system sucks compared to X. We have done well over the years despite that (or maybe because of it?)