I think we need first to understand what the purpose of schooling is. When you say “terrible at delaying gratification” and “learn or die”, is it something that helps one to be an achiever, or something that helps one to live a happier life?
I think the schools have been long useful for 3 main purposes:
Being a (mostly unsafe) training ground for socialisation.
Producing “standardised” packages of knowledge, which is useful for economy, since everyone knows what to expect.
Encouraging people with a tendency to overachieve to excel at it.
Of these three, only the first one is strictly for the benefit of the student, and even at that it is implemented quite poorly. The thing is, the schools were never designed to maximally help somebody in living a happy life. Of course, we’ve never had the luxury to do that, but as we are progressing further and further from the matters of pure survival, it’s something to consider. And that’s what the linked article is really about.
PS I must also mention that the schools are not at the root of this problem. The culture that judges people by their achievement and success is deeply ingrained in the US (compared to, say, Europe), and the schools and parents simply train the kids to survive in it. See also a great (and lengthy) inspection of this phenomenon by The Last Psychiatrist: https://hotelconcierge.tumblr.com/post/113360634364/the-stanford-marshmallow-prison-experiment .
The “common weirdness generator” hypothesis seems quite off to me.
If the individual weird characteristics are independent as random variables, that would correlate with rareness of them occuring in a single species, which we do observe in this case.
If those weird characteristic were actually correlated, that would increase the likelihood of their cooccurance, and make creatures as weird as naked mole rats more common.
So, observation of uniqueness should lead us to believe that they are more likely to be uncorrelated.