> so my mental model

This is the point though. If you know your mental model is wrong, you should update your model rather that perpetuate the errors. It's okay to be wrong and no one is upset at you for being wrong (at least not me). But if you are knowingly wrong, don't try to justify it, use the signal to help you change your model. I know it isn't easy, but recognize that defending your bad model makes this harder. It is okay to admit fault and you'll often be surprised how this can turn a conversation around. (FWIW, I think a lot of people struggle with this, including me. This comment is even me trying to reinforce this behavior in myself. But I think you will also be receptive because I think your intent and words diverged; I hope I can be part of that feedback signal that so many provided to me.)

> so I want to hold the education system accountable

So hold them accountable, not the people in these. I think you intend to blame the system, but I think if you read your message carefully, you'll see a very reasonable interpretation is that you're blaming the person. It is because you're suggesting this is a level of math that everyone should know.

For a frame of reference the high school I went to is (currently) in the top 20% of CA and top 10% of the country. I checked their listings and while there's a 50% participation rate in AP (they also have IB), they do not offer Linear Algebra or anything past Calc I. So I think this should help you update your model to consider what opportunities people have. I think this is especially important because we should distinguish opportunity from potential and skill. I firmly believe metrics hinder the chance of any form of meritocracy in part due to the fact that opportunity is so disproportionate (more so due to to the fact that metrics are models. And you know what they say about all models ;).

If we want to actually make a better society and smarter population, we should not be diminutive to people for the lack of opportunities that are out of their control. Instead I think we should recognize this and make sure that we are not the ones denying opportunities. If we talk about education, (with exception at the extreme ends) I think we can recognize that the difference between a top tier high school student and a bit below average, is not that huge. Post undergrad it certainly grows, but I don't think it is that large either. So I'm just saying, a bit of compassion goes a long ways. Opportunity compounds, so the earlier the better. I'm fond of the phrase "the harder I work, the luckier I get" because your hard work does contribute to your success, but it isn't the only factor[0]. We know "advanced" math, so we know nothing in real life is univariate, right? You work hard so that you may take advantage of opportunities that come your way, but the cards you are dealt are out of your control. And personally, I think we should do our best to ensure that we the dominating factor that determines outcome is due to what someone can actually control. And more importantly, we recognize how things compound (also [0]).

I'm not mad or angry with you. But I think you should take a second to reevaluate your model. I'm sure it has utility, but I'm sure you're not always in a setting where it is useful (like now). If you are, at least recognize how extreme your bubble is.

[0] I highly suggest watching, even if you've seen it before. https://www.youtube.com/watch?v=3LopI4YeC4I