The problem here is the presentation of a counterexample in this way is casting it as an exception, and implicitly confirming the validity of the negative stereotype as the default assumption:

This is also the underlying problem with certain compliments, eg. "Wow, you're a really good developer (unlike most women)!", "You're so well spoken (unlike most Black people)!", and so on.

Given the human ability to rationalize, even a never-ending flood of in-your-face counterexamples is more likely to provoke reactions like "Well, women are just less talented developers on average, of course there are exceptions", and so on.

In South Africa they teach young schoolchildren about the country's apartheid history (and knowing this history is a good thing, because it provides context for the country's modern day inequality).

Sadly there are some older generations who have oppposing (and often contradictory) views of exactly how and why said history played out the way it did.

This disagreement of history often leads to modern day racism.

Sadly it's here to stay - at least for a while still - but I do hope that one day it becomes a thing the past.

EDIT: I see you removed your opening line. Leaving it here for context to my comment.

Hacker culture was born at the zenith of American liberalism, just after its ideals had triumphed over Soviet Union's self-destructing spiral. Those times may never come back, and liberalism itself is on life support :(