Stereotypes like this is just unbelievable in this days and in HN.

I understand the feeling. Unfortunately it's inevitable that stereotypes etc. end up on HN, simply because HN is millions of people. At any moment, some population sample is getting activated by something that appears here and someone will get triggered into commenting. It's important not to generalize from posts like that to the entire community, because if you do it will feel like you're surrounded by enemies, when the opposite is true.

I sometimes find it helpful to replace "HN" with "large statistical distribution" in a sentence. It's usually true and makes things less dismaying.