Schools in the US, at least in theory, don’t teach the philosophical and cultural views of the society. This is a concession to the fact that the US is a multi-cultural society, so teaching values as such would be inappropriate. Kids therefore get some instruction in US history, civics, and government, but you can get through the whole sequence without learning anything about Christianity or Western Europe.
That in itself is teaching values. From kindergarten and up, American schools teach students that diversity is a great thing, and we're all equal, and it's what makes America so special. It's something we're taught to be aware of and cherish. That's something loads of other countries' public education systems don't teach at all, and some even teach the opposite.
How a country teaches values isn't obvious to someone raised within that country. It's just thought to be common sense.
Schools in East Asia, alongside pushing STEM topics are still also vehicles for pushing the philosophical and cultural views of the state through the teachers and curriculum, so I'm not sure why this is befuddling as such.
For a concrete example see Chinese medium schools in Malaysia, where it's not just about them being ostensibly better at teaching math or other STEM topics, but about Chinese language as a proxy for Chinese culture and values.