US education is usually poorly funded and supplemented by local levies so that poor areas get worse resources and the teachers that can make poor pay work while rich areas have fancy schools and can hire anyone. The poor areas generally need more resources, not fewer, to reach parity, because there is more need for things like free food (US schools usually hold back food from poor kids), transportation, and after school programs.
On top of this, the US is socially bankrupt. Community is regularly disrupted and so even is the capitalist nuclear family. Kids are raised in abusive conditions and have high stress households with reactionary parents that often do not care for their kids when they step outsids their preferred views. Students are often tired, hungry, and stressed. So even when they have "access" and "opportunity" on paper, they can't make use of it, logistically or emotionally. They're told to have drive while also lacking the energy and support to make themselves a sandwich.
So most US citizens can't read at a "high school level".
Americans, certainly white Americans, are what Israelis would be if permitted all of their genocidal aims and then told myths for several more generations. Kids are the product of their social circumstances, it is the societies constructed around them that are at fault. But those kids grow up and then become the enforcers of that society or fight against it - and settlers tend to reinforce it.
"Should know better" is basically a question of agency and we always have to think about how we balance thinking of people as products of circumstance vs. moral agents, as the former can lead to sympathy for the oppressor that is counterrevolutionary. But we also do need to understand that it is not just people choosing to be demons, they are deeply propagandized and conditioned to accept and normalize a settler-specific as well as capitalist hosts of violences.
Being disgusted by ubiquitous war criminals is reasonable and on a personal level a righteous position. But if we live in a state with many, we have to formulate our (cynical) approach towards them and construct a political program that accounts for this. Not tailist, but not overlooking the situation nor becoming complacent by writing off every person, which can also happen if you start thinking about how many degrees removed any American is from the imperial war machine. We have to build something oppositional and practical, even if it means small orgs doing outsized direct action or building on and towards generational change, to make joining the war machine shameful and recruit the like-minded. If we hate current society we have to build towards what it could be and have sympathy for who people could have been without this society.
So I agree as well but just wanted to add an addendum that is sometimes missing.